Darin's Weakly Nugget - 2/8/11

Probably all of us have done this, compare two DBLs using our old friend Equals? We know we are treading on thin ice. On the one hand we might wind up asking why '2+2' doesn't equal 4, on the other hand tossing epsilon and In Range and Coerce? around makes one feel a little nerdy and Rube Goldberg-ish. I will never advocate Equals? meaning anything other than all 64-bits matching for DBLs, but, as in horseshoes and hand grenades, 'close' is often good enough. A couple of VIs will help with the DBL comparison issue, although neither is fully satisfactory.
The two contenders:
vi.lib\picture\smith.llb\Almost Equal.vi
vi.lib\Waveform\WDTOps.llb\Check for Equality.vi
Almost Equal.vi:
Pros: Snappy Icon, precision controllable via control.
Cons: Does not handle +/- Inf, not polymorphic, issue with small non-zero values for n1 and n2, epsilon terminal wire stub has a gap (just kidding, who else cares about that?)
Check for Equality.vi:
Pros: Handles Inf, returns precision of match (most times)
Cons: Not polymorphic, 6 digits chosen to represent equality, does not always handle two small, non-zero values well, precision of match retrurns 10 in cases of exact match, less snappy icon.
It would probably be nice to slap the Almost Equal icon onto Check for Equality, fix the bugs, allow the precision to be set by a control, and add polymorphism (mix and match scalars and arrays). That's not a lot to ask, is it? For now, I have the Almost Equal Icon slapped on my homebrew version. I have an option to compare both values to zero, so if a and b are both approximately zero then I consider a approximately equal to b. As is, both are often preferable to Equals? and crossing your fingers.
As a bonus, check out the Almost In Range.vi in smith.llb.

Also check out this discussion from Dec 2005, especially the VI Equal DBL.vi. (Ignore the icon, it's for DBL )
There is even a link for some easy reading.
LabVIEW Champion . Do more with less code and in less time .
Attachments:
EqualDBL.png ‏8 KB

Similar Messages

Stumped on basic problem with floating point math

I can't figure this out! It should be sooooo simple.
Here is the challenge:
I have an incoming time array. For example: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
I want to scale this array by a constant (e.g. multiply by 0.1). So the resulting array should be: 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9
Then I want to calculate the difference between each and every subsequent element in the array. In this example, the difference should 0.1 between every element. But my comparison fails.
See the example below. As far as I can see, the resulting boolean should always be TRUE. But its not.
But if I remove the scaling operation, then it works ok!
Please help!
Solved!
Go to Solution.

It has been awhile since smercurio has had a contribution to his retirement fund, but once again you have "discovered" that there is no exact binary representation for 0.1.
I'd use one of the current "almost equals" comparisons described here:
http://forums.ni.com/t5/LabVIEW/Darin-s-Weakly-Nugget-2-8-11/m-p/1444262
And vote for this if you haven't already:
http://forums.ni.com/t5/LabVIEW-Idea-Exchange/quot-Almost-Equal-quot-functions-for-Float-comparisons...

[svn] 4136: Find loop variables initialized with "weak" types, e.g., NULL or VOID, and

Revision: 4136
Author: [email protected]
Date: 2008-11-18 14:50:38 -0800 (Tue, 18 Nov 2008)
Log Message:
Find loop variables initialized with "weak" types, e.g., NULL or VOID, and
use the variable type used within the loop to normalize the local's type.
Modified Paths:
flex/sdk/trunk/modules/asc/src/java/adobe/abc/GlobalOptimizer.java

Remember that Arch Arm is a different distribution, but we try to bend the rules and provide limited support for them. This may or may not be unique to Arch Arm, so you might try asking on their forums as well.

How to create Auto weakly backup in Windows Server 2012

Hello
1. I want to set auto backup in windows server 2012 Weakly.
2. can i Set auto backup like a normal data copy.

By configuring automatic backup, you can schedule this task according to your choice(weekly/monthly). You can use backup schedule wizard accessed from the Windows Server Backup user interface (Wbadmin.msc).
To schedule backup task by using powershell, please checkout this link :
http://technet.microsoft.com/en-us/library/dd759156.aspx
Also, have a look at here :
http://technet.microsoft.com/en-us/library/cc770757.aspx

Randomly weak/barely functional wifi on Early 2011 Macbook Pro running Lion 10.7.2, out of ideas. Help?

Hey there, boys and girls!
As of August 2011, I am the proud owner of a brand new 13 inch Macbook Pro! Being a tech geek, I have always wanted the opportunity to play with OS X, and I was pretty thrilled by my purchase. However, mere weeks after getting my shiny new computer, the wifi issues started. For no reason at all, it would seem as if my connection was dropped entirely, but checking activity monitor showed that the signal had simply capped off at about 6 kb/s. This issue has continued to randomly strike when I am trying to do something online, and almost always when it is something important. These issues have continued throughout the Fall of this year, and school has kept me too busy to actually get hardcore on this problem. The time has come.
I have read **** near every stinking article on the internet about this problem, and tried every solution that I have seen.
Here is the info I have:
*When the problem occurs, opening activity monitor and choosing "Network" shows a graph that maxes out at 6kb/s, sometimes less. There are characteristic spikes of activity, which are usually between 0 and 2 kb/s. It happens COMPLETELY at random, and for utterly variant spans of time. Sometimes it happens 8 times a day, for hours each time; other times, I get it once a day for about 15 minutes. There is no rhyme or reason to it.
*It happens most frequently on my home network. I am using a Netgear Wireless N router (a new one, at that) which I have configured to serve as wireless router and DHCP server for my Verizon router (on which I have disabled wireless and left essentially as a modem). However, the problem has also occurred outside of my home network.
*It's just my Mac. Every other device connected to the network continues to function normally when the cap occurs.
*Whatever data IS moving when the cap occurs is not user data; in other words, I cannot discern the source of the weak trickle of data that continues when the problem happens. During the problem, I cannot ping in terminal, or use any Internet-connected applications or browsers.
Here are some solutions I have tried which did absolutely NOTHING to resolve the problem:
*Rebooting (duh). Problem remains directly following reboot if it was happening right before reboot.
*Turning wifi off and on again (duh some more)
*Using other browsers/networked applications (also duh)
*Erasing all setting connection files so that they are forced to rebuild (4 plist files in library/preferences/systemconfiguartion)
*Erasing and re-adding networks from the remembered networks list
*Repair disk permissions and disk volume from recovery.
*Reset PRAM
*Keep a terminal window running that just pings a remote server endlessly. This basically cuts off as well when the problem shows up.
No combination of the following worked (and I tried each separately and in tandem, when applicable):
*Change the network location to a custom one
*Set a static IP
*Renew DHCP lease after location reset
I'm basically at my wit's end here. I am technically savvy enough to try basically any solution, but I seem to have run out of options. Does anyone have any solutions I haven't tried? The only other potentially relevant thing I can think of is that I did clone my original 320GB HDD over to a 500GB HDD near the start, but that shouldn't have anything to do with this... right?
I remember being eager to get this machine, but this network plague has me missing my broken-down heap of an old PC. For all it's various shortcomings, was at least able to connect to the **** internet consistently. I thought 10.7.2 would fix the problem... but nope. No help from Apple either. I'm pretty sick of this issue already.

Hey there, boys and girls!
As of August 2011, I am the proud owner of a brand new 13 inch Macbook Pro! Being a tech geek, I have always wanted the opportunity to play with OS X, and I was pretty thrilled by my purchase. However, mere weeks after getting my shiny new computer, the wifi issues started. For no reason at all, it would seem as if my connection was dropped entirely, but checking activity monitor showed that the signal had simply capped off at about 6 kb/s. This issue has continued to randomly strike when I am trying to do something online, and almost always when it is something important. These issues have continued throughout the Fall of this year, and school has kept me too busy to actually get hardcore on this problem. The time has come.
I have read **** near every stinking article on the internet about this problem, and tried every solution that I have seen.
Here is the info I have:
*When the problem occurs, opening activity monitor and choosing "Network" shows a graph that maxes out at 6kb/s, sometimes less. There are characteristic spikes of activity, which are usually between 0 and 2 kb/s. It happens COMPLETELY at random, and for utterly variant spans of time. Sometimes it happens 8 times a day, for hours each time; other times, I get it once a day for about 15 minutes. There is no rhyme or reason to it.
*It happens most frequently on my home network. I am using a Netgear Wireless N router (a new one, at that) which I have configured to serve as wireless router and DHCP server for my Verizon router (on which I have disabled wireless and left essentially as a modem). However, the problem has also occurred outside of my home network.
*It's just my Mac. Every other device connected to the network continues to function normally when the cap occurs.
*Whatever data IS moving when the cap occurs is not user data; in other words, I cannot discern the source of the weak trickle of data that continues when the problem happens. During the problem, I cannot ping in terminal, or use any Internet-connected applications or browsers.
Here are some solutions I have tried which did absolutely NOTHING to resolve the problem:
*Rebooting (duh). Problem remains directly following reboot if it was happening right before reboot.
*Turning wifi off and on again (duh some more)
*Using other browsers/networked applications (also duh)
*Erasing all setting connection files so that they are forced to rebuild (4 plist files in library/preferences/systemconfiguartion)
*Erasing and re-adding networks from the remembered networks list
*Repair disk permissions and disk volume from recovery.
*Reset PRAM
*Keep a terminal window running that just pings a remote server endlessly. This basically cuts off as well when the problem shows up.
No combination of the following worked (and I tried each separately and in tandem, when applicable):
*Change the network location to a custom one
*Set a static IP
*Renew DHCP lease after location reset
I'm basically at my wit's end here. I am technically savvy enough to try basically any solution, but I seem to have run out of options. Does anyone have any solutions I haven't tried? The only other potentially relevant thing I can think of is that I did clone my original 320GB HDD over to a 500GB HDD near the start, but that shouldn't have anything to do with this... right?
I remember being eager to get this machine, but this network plague has me missing my broken-down heap of an old PC. For all it's various shortcomings, was at least able to connect to the **** internet consistently. I thought 10.7.2 would fix the problem... but nope. No help from Apple either. I'm pretty sick of this issue already.

Can anyone tell me or give me a link to the latest response from Apple regarding very real weak wifi signal on what seems to be a batch of both the new ipad and the earlier Ipad2. I have just bought a 2nd hand ipad2 and it has a very weak wifi signal

Over the last week or so I have been trawling the internet looking for references to weak wifi signals on the Ipad2 and was staggered by the sheer quantity of people who seem to have identical issues, not just with the ipad2 but also with the new ipad. What annoyed me most from reading the reams upon reams of comments made on the Apple community forum is the fairly large number of people who seemed to believe that 'these' people were either just moaners and wingers or else they must have something wrong with their router set-up rather than a serious fault with their ipad and it seems all because there ipad in question works like a dream.
Obviously I can only speak from my experience, and that is, I have an ipad2 32GB with wifi, purchased about 6 months ago and it works like dream with a good 2-3 bar wifi signal through 2 thick stone walls over 30 feet away. My router is a standard one supplied by my broadband supplier compatible with all 'g','b' and 'n' equipment. However, over a week ago now I bought second hand genuine ipad2 16GB with wifi from a close friend who has just purchased a new ipad3 to replace his old ipad2 (had it for over a year so no longer under warranty). When I started it up downstairs from my router, where I always use my other ipad2 which has a very strong wifi signal, I discovered that the new secondhand ipad2 I had purchased couldnt find a network signal at all. So after doing network resets and all other 'fixes' on the device recommended, I took it upstairs to my office where the router is based and found that the device could now locate the network, but the signal was lost over only 12 feet from the router!
I quizzed my good friend about this issue and he informed me that it has always been like this since he first purchased it and he never thought that it was a fault, it was just the way it was. When he first aquired the device he did think at the time that this distance was poor, but thought nothing of it as he didnt have any other ipad to measur ethe signal strength against, and as his router was in his living room anyway he nothing of it. Fair enough.
So, there we have it. One ipad2 with a very good wifi signal and another ipad2 with a very poor wifi signal running off the same router, both with the same IOS 5.0. ?
As well as all of the other isues that customers have picked up on, such as 'death grip' (which I must say does appear to happen, but personally i dont think that this is a serious issue if you are aware of this issue and have a strong signal anyway), my experience seems to be a good example of a 'duff' wifi ipad versus a 'great' wifi ipad', an issue confirmed by complaints from a fairly large number of customers who have also reported the same or similar weak wifi signals with both the ipad2 and the ipad3. So, as this shows the weak wifi signal is a very real issue it seems on a batch of ipad2 and 3's, which to my logic is obviously a hardware issue on a batch of early ipad2's and not a software one, otherwise all ipad's would suffer this problem! So, is it a faulty antenna or a faukty network card in an early batch?
So, the bottom line now is, of course, firstly, how can I get Apple to fix my other ipad2 when the warranty has run out? Any suggestions anyone?
Personally I think good Apple customer service should offer a recall with a replacement on this apparent batch of ipads, dont you?

Greetings,
I've never seen this issue, and I handle many iPads, of all versions. WiFi issues are generally local to the WiFi router - they are not all of the same quality, range, immunity to interference, etc. You have distance, building construction, and the biggie - interference.
At home, I use Apple routers, and have no issues with any of my WiFi enabled devices, computers, mobile devices, etc - even the lowly PeeCees. I have locations where I have Juniper Networks, as well as Aruba, and a few Netgears - all of them work as they should.
The cheaper routers, Linksys, D-Link, Seimens home units, and many other no name devices have caused issues of various kinds, and even connectivity.
I have no idea what Starbucks uses, but I always have a good connection, and I go there nearly every morning and get some work done, as well as play.
You could try changing channels, 2.4 to 5 Gigs, changing locations of the router. I have had to do all of these at one time or another over the many years that I have been a Network Engineer.
Good Luck - Cheers,
M.

A fix for the Mozilla Firefox SSL Certificate Validation Security Weakness vulnerability? This appears to be an issue with not revalidating certificates when loading HTTPS pages from cache.

We have to close vulnerabilities for PCI & Cybertrust certification. We have upgraded users running Firefox to version 7.0.1 but we are still receiving the message: Mozilla Firefox SSL Certificate Validation Security Weakness. Researching the issue, it appears to be related to certificates not being revalidated when loading HTTPS pages from cache. The bug report I found is:
Bug 660749 - Firefox doesn't (re)validate certificates when loading a HTTPS page from the cache

cookies.squite answer is Today at 5:15 PM .
New profile, same problem.
We've already established it is not a add-ons problem but obviously there will be less add-ons in this new profile to help exclude.
Since there is two PC profiles on the PC, I tried the second profile, same problem. Used the RESET FF function on the second PC profile...same thing...even followed the instruct for uninstall &re-install...same problem.
(3) different virus scanners, no hard core problems.
Suspect how I have something in Windows setup that no one else is using?

Community Nugget Series: Application Development- Installment 1

Installment 1: Code by intention and basic code components
In
this Nugget series we will discuss application development, the
different ways we use to access data and information, develop a GUI that
has Controls, Indicators and other front panel objects accessable from
sub.vi's in multiple ways and explore a software developers approach to
LabVIEW without OO but exposing OO concepts. I'll be starting with
basics and moving to a real-world app designed specifically for Test
Automation. Many of the concepts have wide ranging application but as
this is my first "Nugget" and "Series" I'll chose to speak from my
strengths. I hope you all forgive me.
So lets show how to start: I do it thusly
NOTE:
The vi hasn't even been saved yet! The FP and BD are blank (OK - Use a
template if you want to save time but for this demo I'm starting from
scratch)
This is where software starts, with the end
user(s) firmly in mind! <Sea Story> I grew up as an Electronics
Technician. One day a test instrument rep demo'd a new o'scope with
advanced math functions. We were impressed with the capabitities -
untill it took 5+ minutes to perform the operations. Automate that!
[prompt user "please wait while device X does some math. Ensure
sliptick oil resivour remains above "critical.""]   We called it "Same
Day Display." The instrument MFG did not think about the end uses for
the product when archetecting the system. <
Let's not do that here.
Overall Achietecture: 4 main interlocking Queued P-C loop vi's
defined as: (If I may borrow from a business case to aid visualization)
Corporate Communications ( CC or GUI):
Executive:
Operations:
Accounting:
Each of these loops Consumes exactly 1 Queued loop:
1:
CC is primarrilly an Event Loop. After initialization it responds to FP
events. These events can be caused by direct user action or by
indirect actions when something in the application generates an event
the GUI needs to respond to. It produces the "Executive" Queue and may
generate events. It keeps the user informed and happy.   It is the
primary abstraction layer between the developer and the user. If the
user can do it CC needs to respond - If the developer expects the user
to do something it Must be intuitive or explained by Tip Stips and / or
on screen instructions.
2: Executive is a QSM
(Queued State Machine) it consumes the "Executive" Queue, generates the
"Operations queue, and may generate events for CC. This is the main
abstraction layer between the developer and the application
enviornment. In this demo we will perform "Tests" defined as a sequence
of things do much like the tasks your manager asks you to take to
acomplish an objective. Its the manager scheduling how when and what to
do and has a really great Admin department that knows the business,
what can be done by the Ops dept and has a list of activities that
should be performed to satisfy the customers (yep! sequence files!)
We'll get to those in another nugget in the series!
3:
Operations is another QSM it consumes the "Operations"
Queue, generates the "Accounting" queue, and may generate events for CC
. This is the main abstraction layer between the developer and the
system components or HAL (Hardware Abstraction Layer). All interaction
between the application and other resources (except the file system and
KVM) takes place here. Again- we'll save that for another nugget.
4:
Accounting is another QSM it consumes the "Accounting"
Queue, generates "Executive" queue, and may generate events for CC .
Its job is to let the Executive know what the result of the operations
are so managemant can make an informed desicion on what to do next. And
it files reports in whatever format the Admin assistant's policy says to
do it in.
Each of these four main functions exist in all applications and all LabVIEW code. Here is CC GUI A.vi after saving
the
GUI responds to user clicks of "stop"(Tip Strip Val ="Press to stop
this vi ") and the vi changes state on the next loop iteration.
Executive
functions are encapsulated in the while loop itself Management is
simple: "Unless the last operation was True do the same thing again" (and the constant 10 is our admin assistant!!!! change it and the app behaves different)
Operations
"list of things the vi knows how to do" is limited to Update i, Wait
(n)mSec and (AN,D not then, no data dependancy so we are multitasking!)
read Stop
Accounting is in the condition terminal reporting the value of
stop- and we chose not to report anything- could have reported Array of
Stop, Last i, or any of the values we see either to the FP, any file
whatever! just illustrating a point.
Our requirements a a bit more detailed and we'll get back to the GUI next nugget:GUI FP object encapsulation.
Jeff

F. Schubert wrote:
Thanks for this nugget. The business case model looks interesting. I'm looking forward to see how this will evolve.
As a side note, I always like graphical sketches. So the basic idea of the interaction between the business entities could be drawn using boxes and arrows.
Felix
As ususal you and I are on the same page.
These images ...
and
appear im the documents I posted in this thread where I talked about doing the design first (consistancy).
The high level organizational, interaction diagrams are what I try to sketch up mentally during kick-off meetings. I use a variety of methods to get the information I need for these diagrams depending on what I know going in and the nature of the customer but... I don't let the meeting end until i have a picture tht models a system that meet the neeeds.
The diagrams doc what the customer wants, splits up the work into clean concise chunks, establishes responsibilities, needs, and the chararcter of each. In short they go a long way toward defining the design.
And for those apps you only up-date every three or four years...
There ain't nothing like those diagrams to gt you back into the same frame of mind you where when you designed it.
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

My internet having a weak connection than before...

for some reason, I am in my room using internet on wifi have been really weak although i am right next to the cable....
It used to have about 655 kb/s in, now it goes about 135 kb/s in and sometimes 1-40 kb/s... does anyone have the same issues?? i am also looking at others but in case if that's not their case... thanks... and my macbook stat is leopard and t's working really fast before i updated to 10.5.2 then
afterward, it's been really slow and inconsistent....
can anyone help??
thanks
Message was edited by: chubbydw331
Message was edited by: chubbydw331

Refer to this thread:
http://discussions.apple.com/thread.jspa?threadID=1715837&tstart=0
Check your logs as indicated in System Profiler, check Airport card type, there are 2 to my understanding, Atheros and Broadcom. I have both flavors of black macbooks, the older one with Atheros card doesn't appear to have the problem but it is in the same room as the router.
If your problem is as described above the only current fix is performing an Archive & Install back to 10.5.2. Most Leopard DVD's are 10.5.1 so you would have to apply the 10.5.2 combo update after performing the A&I. Going back to 10.5.2 should restore Airport card performance.
Note: If your router is in the same room, you might also try going outside with the laptop and testing connectivity, N is supposed to work better farther away (assuming the WIFI card is performing correctly).
All the testing I have done (3ea Archives and Installs) shows the problem is fine with 10.5.2 and only breaks when 10.5.3 or higher is applied. Since I can "restore" and fix the problem, it tells me it is a software problem initiated with the release of 10.5.3. The logs should verify that.

My iPad 2 picks up very weak wifi signal, but my iPod touch 5 in the same spot picks up super strong signal. What can I do to change this?

I have an iPad 2 and am iPod touch 5. Yesterday, my iPad all of the sudden did not want to pick up ANY signal at all in my house. It's like it completely give up on wifi, while my iPod and my laptop works just fine in the same spot. (I have an upstairs bedroom, while the router is downstairs in the kitchen).
So I have been trying yesterday to get it to work so what I have done is completely wipe the memory clean after I backed it up on iTunes. After resetting it, I restored it. Still nothing. So I tried to take my iPad down nearer to the wifi router, and OMG it picked up the wifi signal! WHUT?!? It didn't yesterday though...
But now whenever I am up in my bedroom, my iPad would not pick up the wifi at all, or if it did, the wifi would be super duper weak! But two days ago, it was PERFECTLY okay! My iPod and laptop that is sitting right next to the iPad up in my bedroom pick up the signal completely fine.
Can someone help me? What should I do? Is it problems with my iPad or would it be my router that is the problem?

Some things to try first:
1. Turn Off your iPad. Then turn Off (disconnect power cord for 30 seconds or longer) the wireless router & then back On. Now boot your iPad. Hopefully it will see the WiFi.
2. Go to Settings>Wi-Fi and turn Off. Then while at Settings>Wi-Fi, turn back On and chose a Network.
3. Change the channel on your wireless router (Auto or Channel 6 is best). Instructions at http://macintoshhowto.com/advanced/how-to-get-a-good-range-on-your-wireless-netw ork.html
4. Go into your router security settings and change from WEP to WPA with AES.
5. Renew IP Address: (especially if you are droping internet connection)
    •    Launch Settings app
    •    Tap on Wi-Fi
    •    Tap on the blue arrow of the Wi-Fi network that you connect to from the list
    •    In the window that opens, tap on the Renew Lease button
6. Potential Quick Fixes When Your iPad Won’t Connect to Your Wifi Network
http://ipadinsight.com/ipad-tips-tricks/potential-quick-fixes-when-your-ipad-won t-connect-to-your-wifi-network/
~~~~~~~~~~~~~~~~~~~~~~~~~
Wi-Fi Fix for iOS 6
https://discussions.apple.com/thread/4823738?tstart=240
iOS 6 Wifi Problems/Fixes
How To: Workaround iPad Wi-Fi Issues
http://www.theipadfan.com/workaround-ipad-wifi-issues/
Another Fix For iOS 6 WiFi Problems
http://tabletcrunch.com/2012/10/27/fix-ios-6-wifi-problems-ssid/
Wifi Doesn't Connect After Waking From Sleep - Sometimes increasing screen brightness prevents the failure to reconnect after waking from sleep. According to Apple, “If brightness is at lowest level, increase it by moving the slider to the right and set auto brightness to off.”
Fix For iOS 6 WiFi Problems?
http://tabletcrunch.com/2012/09/27/fix-ios-6-wifi-problems/
Did iOS 6 Screw Your Wi-Fi? Here’s How to Fix It
http://gizmodo.com/5944761/does-ios-6-have-a-wi+fi-bug
How To Fix Wi-Fi Connectivity Issue After Upgrading To iOS 6
http://www.iphonehacks.com/2012/09/fix-wi-fi-connectivity-issue-after-upgrading- to-ios-6.html
iOS 6 iPad 3 wi-fi "connection fix" for netgear router
http://www.youtube.com/watch?v=XsWS4ha-dn0
Apple's iOS 6 Wi-Fi problems
http://www.zdnet.com/apples-ios-6-wi-fi-problems-linger-on-7000004799/
~~~~~~~~~~~~~~~~~~~~~~~
How to Boost Your Wi-Fi Signal
http://ipad.about.com/od/iPad_Troubleshooting/a/How-To-Boost-Your-Wi-Fi-Signal.h tm
Troubleshooting a Weak Wi-Fi Signal
http://ipad.about.com/od/iPad_Troubleshooting/a/Troubleshooting-A-Weak-Wi-Fi-Sig nal.htm
How to Fix a Poor Wi-Fi Signal on Your iPad
http://ipad.about.com/od/iPad_Troubleshooting/a/How-To-Fix-A-Poor-Wi-Fi-Signal-O n-Your-iPad.htm
iOS Troubleshooting Wi-Fi networks and connections http://support.apple.com/kb/TS1398
iPad: Issues connecting to Wi-Fi networks http://support.apple.com/kb/ts3304
WiFi Connecting/Troubleshooting http://www.apple.com/support/ipad/wifi/
How to Fix: My iPad Won't Connect to WiFi
http://ipad.about.com/od/iPad_Troubleshooting/ss/How-To-Fix-My-Ipad-Wont-Connect -To-Wi-Fi.htm
iOS: Connecting to the Internet http://support.apple.com/kb/HT1695
iOS: Recommended settings for Wi-Fi routers and access points http://support.apple.com/kb/HT4199
How to Quickly Fix iPad 3 Wi-Fi Reception Problems
http://osxdaily.com/2012/03/21/fix-new-ipad-3-wi-fi-reception-problems/
iPad Wi-Fi Problems: Comprehensive List of Fixes
http://appletoolbox.com/2010/04/ipad-wi-fi-problems-comprehensive-list-of-fixes/
Connect iPad to Wi-Fi (with troubleshooting info)
http://thehowto.wikidot.com/wifi-connect-ipad
Fix iPad Wifi Connection and Signal Issues http://www.youtube.com/watch?v=uwWtIG5jUxE
Fix Slow WiFi Issue https://discussions.apple.com/thread/2398063?start=60&tstart=0
How To Fix iPhone, iPad, iPod Touch Wi-Fi Connectivity Issue http://tinyurl.com/7nvxbmz
Unable to Connect After iOS Update - saw this solution on another post.
https://discussions.apple.com/thread/4010130
Note - When troubleshooting wifi connection problems, don't hold your iPad by hand. There have been a few reports that holding the iPad by hand, seems to attenuate the wifi signal.
Wi-Fi or Bluetooth settings grayed out or dim
http://support.apple.com/kb/TS1559
~~~~~~~~~~~~~~~
If any of the above solutions work, please post back what solved your problem. It will help others with the same problem.
 Cheers, Tom

MathScript Nugget #19: Sharing Data With Other Applications

In MathScript Nugget #18, we looked at ways to transfer data between MathSript and the rest of LabVIEW. In today's nugget, we'll see some of the different ways that MathScript can share data with programs besides LabVIEW.
The most common way to share data between programs is by reading and writing files. MathScript supports several file formats that are recognized by other programs. The ones we'll touch on in this nugget are MLV, MAT, CSV, TXT, TDM(S) and XLS.
The easiest way to bring data into MathScript is with the 'load' function. The help topic for this function does a great job of explaining it. The load function will bring in a group of variables that have been saved to a file earlier. The most common formats that load supports are:
MLV files created with MathScript save function
MAT files created with version 6.0 or earlier of The MathWorks, Inc. MATLAB® software
TDM and TDMS binary measurement files created in LabVIEW or DIAdem
The load and save functions are great for storing off a group of variables to be used again in a future session of MathScript. You can do the same thing using the Operate>>Load Data... and Operate>>Save Data... menu items in the MathScript Window. These support the same file formats as load and save.
The best formats to use if you want to share data with other applications are TXT, CSV, and XLS. MathScript has special funcitons to read and write each of these formats. The functions, such as fread_csv and fwrite_xls, are all members of the support class.
The last way to read and write data files with MathScript is to use a custom file format. MathScript supports common file operations like fread and fwrite. You can use these functions to create or import files of any binary or textual format.
There's one last way to move data out of MathScript without using files. You can copy data from the MathScript Window or MathScript Probe as tab-delimited text to your OS clipboard. You can then paste this text to a text editor or spreadsheet program.
Hopefully now you have an idea of the many ways to move data into and out of MathScript.
MATLAB® is a registered trademark of The MathWorks, Inc.
jattas
LabVIEW MathScript R&D
ps Check out more MathScript Nuggets!

TDM and TDMS are also excellent file formats to share your data with other applications. National Instrumenst offers free libraries and add-ins to access TDM and TDMS files with e.g. Excel, OpenOffice Calc or The MathWorks, Inc. MATLAB® software. Have a look at this page to
Find Resources for Reading and Writing TDMS Files in Third-Party Products

One more nugget: Chart zoom with the "Mouse Over" effect

Hello all.
Just read my signature first, it might explain a lot. I do not intend to compete with Darren and I don't think this "nugget" (at least it supposed to be one) will amaze any of the LV veterans and this forum is rich of them. But maybe it will bring some new ideas to some of you or maybe it will be useful for some LV beginners (like me). It is very likely, my code will have some lapses, but please be gentle pointing that out to me. If you feel a need, you can always optimize the code and develope it further. Just don't forget to share!
So back to the point.
I am developing a project using LV. In my program there is a waveform chart which has to show 4 plots. Depending on the length of the X Scale, it sometimes gets hard to see the plots clearly because of their density.So I decided that I need a tool, which would zoom the chart in. And this is what I have came up with after a few "Google" searches to check which part of the bike is already invented and also a bit of programming by myself.
Maybe you guys (at least the veterans) know the BetterVIEW Consulting LV example where they have implemented the Mouse Over effect. So a part of their example has been used in this tool and part of the credit must go to them. I thank them a lot
This tool uses a cluster and its property of visibility to show/hide the cluster depending on if the current position of the mouse cursor is in the desired range or not. The program also gets the image of the chart and returns the subset of the image. The subset is taken for the area arounf the mouse cursor. So if you move the mouse, the zoomed in area will also chage in response. After that, the subset of the image is zoomed in for better view.
The user might chage the zoom factor during the execution. Also it is possible to turn the zoom option On or Off if you don't wish to see it for the moment.
This is how the front panel looks like:
And this is the image of the block diagram (see the attached files for the vi, the VI Snippet tool distorts the code too much, so I haven't added it):
I haven't found anything the same in the forum. Yet I'm a newbie here and I don't have that much experience surfing it. If it wouldn't be something new (in the forum, not necessarily to some of you personally), just ignore the thread. I hope this was worth your time and your attention.
Good coding
Message Edited by Giedrius.S on 02-11-2010 12:46 PM
While evaluating my code please have in mind that I am a LV novice. Therefore sometimes my code might violate some coding rules that I have to learn about myself. But how else could I do that...
Chart zoom with "Mouse Over" effect
Attachments:
Zoom.vi ‏198 KB
Mouse_pos.vi ‏20 KB
Check_pos.vi ‏18 KB

Very nice Giedrius.
It takes guts to "step up to the chalk board" so I will do what i can to give you some ideas to think about. This is similar to the type of feedback I offer durring our in-house code reviews.
1) The floating property nodes outside the loop are not sequenced by wires so they could execute after the loop starts. Sometimes this could cause weird errors. Seq with the error cluster.
2) Property nodes can be re-sized so you can apply more than one property setting in the same call. Property node have to execute in the UI thread (which is single threaded) so using a single nodes will force a single context switch rather than one for each.
3) Setting the same property repeatedly in a loop just burns CPU. THe Scale min for both X an Y can be moved outside the loop ?
4) THe Wait Until Next ms" function does not get used in any of my code. It is not a way to get a fixed wait but rather a random wait. If you code completes 1 ms after the next multiple, the delay is double less 1 ms. If you have multiple loops using them and it f the delay for each are not unique prime numbers, then the "Wait until next ms multiple" is a good (cough cough) way of getting them all to wake up at the same time and fight for the CPU.
5)An Event Struture to monitor mouse enter/leave and mouse move (this would have to be a sepearte loop) is easier on the CPU than polling.
6) Is that math in the case to handle the Chart position on the FP? If so then using the property nodes for the chart to find its postion will let you code adapt to GUI changes.
7) Right to left wires are not well recieved.
8) A Bundle by Name is prefered over a "Bundle" since it is self documenting. I know the Picture function so I can see that is the rectangle you are specifying but reader not famliar with that function would not be able to "READ" the code without poking at it.
9) THe event structure would also help with setting the Zoom factor. Only poke it when you have to.
That is all that comes to mind at the moment.
Again thank you!
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

HT204409 I have a new iphone 5 and it won't connect to a wireless router that my old iphone 3GS would pick up. Is there a compatibility issue with some routers or is the antenna weaker in the new iphone 5?

I have a new iphone 5 and I can't pick up a wireless router that I could use with my old iphone 3GS. Is there an issue with the new iphone and is the antenna weaker than the 3GS?

Please read this :
https://discussions.apple.com/message/20053332?ac_cid=tw123456#20053332
Well I copyed it to you here.
Re: Anyone still having IOS 6 wifi issues?
created by mpa9366 in Using iPad - View the full discussion
Having done a lot of reading today and having found a very good online tablet magazine (will post link tomorrow) there seems to be a few tech bods onto the problem.
The magazine I was reading identified wifi problems within hours of the ios 6 release and have been analysing since then with almost daily updates - the story seems to be:
The apple authenthication transmission is normal, it should slip through event prior to a full handshake with the host network being completed - however if not authenthicated then apple will not permit the device to connect (kills the connection) this is designed to protect apple from counterfeiting. So thats problem 1 if you dont receive a token from apple.
Problem 2 is that ios 6 only supports ipv6 (the new ip protocol) whereas outside silicon valley a large proportion of routers modems etc are still ipv4 protocol.
So youre locked into ipv6 in a world where ipv4 devices are everywhere and apple have not allowed for the ability to handle both protocols. This is like GM telling you your car requires an upgrade, everything will improve etc and as part of the upgrade fits a fuel cell motor and stays silent when their upgraded vehicles are simply parked up because they cannot get fuel.
A very basic expectation would have been dual protocol handling - we know the HW supports ipv4 as all wad fine on ios5.
So its going to be hit and miss with networks - more hit than miss in techy areas like silicon valley, but more miss in places like where I am - a small town in rural Switzerland.
Only apple can fix this with a patch to enable ipv4 protocol handling.
There you go. you just need to buy a new router, I'm sure Apple has one for sale, cause it's not there fault for sure.
Wonder why people start to migrate to other devices ?

I bought my iPhone 4 open line in Vancouver, Canada last week for use here in my home base in Bangkok, Thailand. But when I tried using my Thai sim, I get a very weak signal, if not a weak signal, then a no service status. What do I do?

I bought my iPhone 4 open line in Vancouver, Canada last week for use here in my home base in Bangkok, Thailand. But when I tried using my Thai sim, I get a very weak signal, if not a weak signal, then a no service status. I also have very weak wifi reception. What do I do?
I already tried the following:
a. Turned the phone off and then on.
b. Checked all wifi connections – no problem given that all our laptops and desktops can connect seamlessly.
c. I tried restoring the phone to original factory settings via itunes
d. Tried resetting the phone.
e. Tried different microsims from all networks
f. However, all methods failed given that the network reception is very weak and often reflects – “no service”. And with regards to the wifi reception It has difficulty in reading even the signal right in front of the wifi router.
I went to two Apple resellers here in Bangkok and requested that they please look at my Iphone and have it serviced. I was frustrated when they said that given that I bought my phone in Canada, they are not able to support me and should instead try to contact the Apple store in Canada.
I went to apple.ca website and went to the expresslane support and I was said to register and callback. Tried calling the 1800 number but given that I was in Thailand I had difficulty getting a connection.

1st sentence, 4th page of the iPhone warranty found here:
Apple may restrict service to the country where Apple or its
Authorized Distributors originally sold the hardware product.
From the Repair terms and conditions found here:
9. Availability of Service.
Apple may restrict service to the country where Apple or its authorized distributors originally sold the
hardware product, and to the countries listed in the table below. A list of authorized distributors is
available online at:
http://images.apple.com/legal/warranty/docs/iPhoneAuthorizedDistributors.pdf
If you do not believe that, then see these search results which confirm my statement.

Community Nugget 4/08/2007 Action Engines

Action Engines, What are They?
“An action engine is Ben's term for a functional global which includes extra actions other than just holding the data.”
(tst , 03-13-2007 01:18 PM)
In a nut shell tst has nailed it except for the “Ben’s term” part. I was originally exposed to the term "Action Engine"
by reading the book ""LabVIEW Applications Development A Course on Advanced LabVIEW Programming Techniques*”. But
before I get into details of the Action Engine (AE), I will attempt to clarify some terminology.
Functional Globals
Functional Globals (FG) are VIs that are functionally equivalent to LabVIEW globals. Functional Globals store
information. You can read them or write them and that is it. No fancy stuff. Functional Globals are also referred to as
LV2 globals because LV2 did not have globals but it did support Un-initialized Shift Registers (USRs). The USR is the
entity that stores the information.
USR.jpg
USR’s
Shift Registers (SR) come in two varieties “Initialized” and “un-initialized”. The presence or absence of a wire
feeding the SR from outside the loop distinguishes how LabVIEW will implement the SR. If there is NO wire feeding a
shift register (A), then the SR is not initialized. This is called an “Un-Initialized Shift Register”. The USR variety
is implemented as static buffer that is re-used from call to call. The values written to the USR in and earlier call
persist for access (B) in latter calls**. A Functional Global exploits this behavior by implementing two methods of
interacting with the contents of the USR.
Functional Global.JPG
In the “Write” action (not shown) the value of “Numeric in” is placed in the USR. In the “Read” action the contents of
the USR are returned via Numeric out.
Action Engines
An Action Engine (AE) can be thought of as a machine (Engine) that performs some useful task (action) often on
something (typically but not limited to data in a USR). Functional Globals are very specific type of Action Engine.
They have two actions “Write” and “Read”. They operate on the data stored in the USR either by replacing or using the
contents of the USR. So AE’s are a superset of Functional Globals. In many documents the terms AE and FG are
interchangeable. A recent poll on LAVA has indicated that Functional Global is the most popular term. Since this Nugget
was prompted by answering the question “what is an AE?” in the remainder of this document you will find that I will
generally use the term AE.
Do What to What?
AE design revolves around the ways the shared resource must be accessed manipulated or monitored. In a Functional
Global, the actions “Write” and “Read” are appropriate. That is not necessarily the case for AEs. AEs can have entirely
different set of actions depending on the interaction requirements for the information stored in the USR. A short list
follows.
A Configuration AE could allow for multiple processes to share a single copy of the system configuration (in a USR) by
providing actions like “Set Device ID”, Set Device ON-Line…
A hardware device can be realized as an AE that presents actions appropriate to the physical phenomenon being measured
or controlled.
A DO Port Controller AE could store a reference to the physical device in one SR and the port status in another SR and
have action like: Set Main Motor On”, “E-Stop”, …
An Instrument can be implemented to store the device name and settings with actions like “Set Input ON” “Auto-Scale Y”
and “Get Trace”,…
Screen Stacks can be implemented by using control references in one USR and maintain a screen view stack in another
then implementing actions like “Set Config Screen”, “Set Login Screen”, “Back”…
Users can be managed using an AE with action such as “Add New User” “Set Password”, “Disable User”…
The list goes on and is limited only by our imagination. Here is an example that shows how a running average can be
maintained.
Running_Average_Example.jpg
Running Average Example
The Running Average Example shown above shows how a running average can be maintained using an AE. The AE is
initialized before the While Loop executes. On each iteration of the loop the simulated measurement value (random
number) is used to update the history of all measurements (Add Number(s)) and the mean is calculated (Calc Mean).
Please note that although the buffer of all measurements is affected in every step of this example, the buffer (USR in
the sub-VI) contents are never part of this VI’s diagram. Since the history is stored in the sub-VI, the history can be
acted on from more than one thread as shown below.
Parallel_Loops.jpg
In the parallel Loops Example the history is initialized and then two loops run in parallel with one updating the
history and the other plotting the average. Since the History resides inside the USR of the sub-VI the two while loops
are effectively sharing the same block of memory, the block used to store the USR. The Sub-VI was implemented as shown
in the following sequence of images.
Init.jpg
As was the case with Functional Globals, the actions are implemented as a type def’d enum***** driven case structure.
Appropriate code is present in each case to realize the intended actions. In the “Init” case, contents of “Array in”
are used to initialize the history. In our example above we did not pass an initial array value. Therefore the “Init”
resets the history (cleared the array).
Add Num.JPG
The operation of the AE when the “Add Number(s)” action is called varies depending on its usage. If the caller passes a
non-empty array, it is appended to the array. Alternatively, passing a value via the Numeric in” control, and leaving
the “Array in” un-wired adds a single element to the history. We used the Numeric In input so we were continually
building our history one value at a time.
Calc_Mean.JPG
When the “Calc Mean” action is invoked, the average is calculated and returned.
This Nugget is continued in the next post
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction
Solved!
Go to Solution.

Nugget continued
The Traffic Cop Behind the Scenes
A detail I have not mentioned up until now is that AEs should be implemented as VIs that are not reentrant***. VIs that are not reentrant can only be executing in one context at a time. LabVIEW will ensure that if there is ever a situation were two contexts are attempting to act on the same AE at the same time, LabVIEW will schedule the first and the subsequent will wait until the first call completes. This is similar to a traffic cop preventing more than one vehicle from entering an intersection at the same time. The Traffic Cop is illustrated in the following timing diagram were we look at how the processing of two threads is affected by using a single AE.
Execution_Timeline.JPG
In the figure above the processing time of two processes “P1” and “P2” are illustrated by a red or blue solid arrow respectively. In the parallel loops example shown earlier, P1 could be the “Calc Mean” loop and P2 could be the “Add Number(s)” loop.
t0 - t1
Both processes are executable and run their assigned tasks. Neither process is accessing the AE.
t1 – t2
P2 continues to run while P1 calls the AE. Since the AE is idle it is available to run so P1 continues execution running inside the AE until all work inside the AE completes. The dotted arrow shows that the thread for P1 is executing in the data space allocated for the AE.
t2 –t3
At t2 the AE terminates and both process run as in t0 – t1.
t3 – t4
This time segment is similar to t1 – t2 with P2 running in the AE.
t4 – t5
Similar to t2 – t3 the AE terminates and both process run.
t5 – t6
Similar to t1 – t2. P1 take control of the AE.
t6 - t7
At t6 P2 attempts to call the AE. Since the AE is not idle it is not available to run. P2 is placed in a resource wait state (it is NOT running) waiting for the resource to become available. The dotted horizontal arrow indicates the process is not executing.
t7 –t8
At t7 the call of the AE by P1 that started at t5 completes and P1 continues to execute outside of the AE. When the call by P1 completes the AE becomes available. The process P2 is marked as executable. The scheduler includes P2 in its executable threads and the AE is available. P2 then executes inside the AE until the call completes.
The Beauty of the AE
This behavior of a non-reentrant VI is a wonderful feature we can exploit to eliminate race conditions. Race conditions are the nemesis of many a developer. In hardware this was solved with clocked enabled logic. In LV we solve race conditions with Queues, Semaphores, Rendezvous, Occurrences, and Action Engines!AEs can eliminate race conditions when all operations involving updates of the data stored in the USR are done INSIDE the AE. A very simple illustration of how the encapsulation of USR manipulation is shown in the following set of examples.
Port_With_Global.jpg
This VI is intended to demonstrate how two bits of an eight-bit port can be used to control the running state of two pumps. To illustrate the control process, one pump will be set running at start-up and then every half second the state of both pumps will be toggled to simulate switching of the supply. This example uses globals and fails miserably.
Port_With_Global.jpg
In this example we start out by initializing a global variable so that bit “1” (zero based) is the only bit set in an array of eight bits. This turns on Pump 2 to start. Then the “Port Update” and a “State Change” loops run in parallel. In the “Port Update” loop the state of the port is read from the global and used to update the GUI.
In the “State Change” loop, the port status is read and the first Boolean is inverted before being written back to the global. Similarly for the second Boolean. Since the read of the globals both occur before the subsequent data processing, one of the threads will be processing old data.
Port_With_Action_Engine.jpg
The Action Engine version codes up the same way as the global version but now all of the data manipulation of the port states are encapsulated in the Action Engine “Port Controller”. This encapsulation ensures all operations involving the data in the USR are forced to happen sequentially even though we did not have to implement any code to achieve this affect.
The key point to take away from this example is a shared resource (the port status in the case) when implemented as AEs come with resource contention resolution built in provided that all manipulation of the shared resource takes place inside the AE.
Action Engines to the rescue!
Action Engines are not a replacement for Queues, Rendezvous and the other synchronization techniques. They are typically called for when your design dictates that a single resource must be shared by more than one parallel process and none of the LabVIEW provided techniques are sufficient. They require a design of their own to ensure they work correctly. They also have to be developed and supported.
This Nugget is continued in the next post
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Darin's Weakly Nugget - 2/8/11

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