How come in frequency/ Time domain there is no negative axis?

Hi guys!
I m doing a tutorial to represent sine wave in its frequency domian? ALthough i get the 2 compoents from(exp(jwt)*cos wt) but all the frequency components are in positive domain???
Its completely different from what I had studided?
AM I wrong?
Pls correct... Learning in jeopardise...lolx..
Thank u!

See reply here: http://forums.ni.com/ni/board/message?board.id=170&view=by_date_descending&message.id=322149#M322149

Similar Messages

How come in frequency/ Time domain in a waveform graph there is no negative axis?

Hi guys!
How come when i m converting a graph never exists in negative domain?
Actually i m doing a tutorial of sine

duplicate
Message Edited by mathan on 05-08-2008 02:01 AM

How come now every time i throw something into the recycle bin it asks for my password and when I do it doesn't show in my bin help please!

How come now every time i throw something into the recycle bin it asks for my password and when I do it doesn't show in my bin help please!

You're throwing away files that either don't belong to you or are in a folder that doesn't belong to you. Since your user account has Administrator privileges, it just ask you for authentication, else it would forbid the operation.
To better understand the concept, select one of your files from your home directory and press Control-I. In the info window, check the Sharing & Permissions section at the bottom. Do the same with one of the files that asks for the password.

How to transfer from time domain data to FFT domain

I have built Labview program to acquire data, which in time domain I would like to change it to frequency domain in the same program for further processing,

There are a large number of shipping examples. Open the example finder, go to the search tab and either enter fft or spectrum as the search keyword. However, I think all require that you have the full version of LabVIEW and not the base version.

How come that the time machine backup takes 5 days to sync 200 GB over the ethernet?

I'm really not happy with the backup speed of the time machine. it has been 1 day and half that it is syncing and for now just 36GB are done of 210GB.
The remaining time estimation is ridiculous around 5 more days?
How come this is possible?? I cannot move my mac pro anywhere else it needs to be plug-in 24/7 to the Ethernet and power, of course hoping that everything goes already during these 5 days to backup.
I've tried different things, I've check my disk for issues also for permission issues none existed.
I've tried to restart the backup from scratch, even some times it start fast it slows down to a very low transfer rate, and now the current rate of transfer is around 1KB or lower :S
The soul purpose of the time capsule is to do backups but at this speed rate it's useless, and from what I saw it happens to other people.
I must have being doing something very wrong, can anyone help me or give me suggestions?
Regards
P.S. Mac pro 13'' early 2011 with 8 GB, Mac OX 10.7.5

The latest update to Lion.. 10.7.5 added slowness of TM as a new feature.. (There are no bugs just features).
Until Apple sort out their beta testing I would recommend a different backup software. CCC, SuperDuper, Chronosync.
The issue from reading the various posts is affecting everyone.. including people using external drives.
Welcome to the new Apple beta program.

How come when every time i open ff i have the same 2 tabs instead of the one I choosed in my options

'''''texte en gras'''''
in "option internet" & "general" & i chose "new tab" for my home page, but every time i open firefox i have two tabs that loads, one is the tab i asked for, but another one creep in there, it is an old web page where i downloaded something from there after installing firefox, i don't know if it is because i went to that site right after dowloading firefox 6.0 it is like the web page stuck there with my home page and i tried everything but nothing works...
please forgive my english, i am not bilingual yet...thank you

Another user had a second tab opening and it was caused by one of his extensions.
You can check for nonessential or unrecognized extensions on the Add-ons page. Either:
* Ctrl+Shift+a
* orange Firefox button (or Tools menu) > Add-ons
In the left column, click Extensions. Then, if in doubt, disable.
Usually a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the Add-ons page and click one of the links as the last step.
Does that get rid of the extra tab?

How come my battery timer remains at 4:47 no matter what

When I'm connected to AC power or have it running from the battery, it remains at 4:47.
I mostly use it connected to AC, with brief use of the battery if there isn't any ac around. Of course when I plug it in the power cord light shows orange to indicate that it's charging. But the battery timer never changes anymore.

I had a similar problem, but my cord did not light at all. I also had other problems and the reseller replaced my MBP.
You may need the battery; check the serial numbers on web site.
Also call Apple Support.

How to enhance frequency resolution of fft spectrum on x-axis

Dear Sir
I get the frequency spectrum of my real time signal. Frequency span that I want to analyze is 0~500hz. I get that span by setting the sampling rate. But the frequency resolution coming on graph is of 100hz (as shown in attachment). My requirement is to have frequency resolution of 10hz with same frequency span. Please guide me how can I achieve this.
I shall be thankful to you
Kind Regards
Muhammad Irfan
Student
UTP Malaysia
0060149087570
Solved!
Go to Solution.
Attachments:
fft graph1.JPG ‏40 KB

I set the dt value to 0.002. For this I set sampling rate 2000hz and no.of samples 1000000. In this way I achieve frequency span of 250hz. But resolution is still 100hz (as shown in attach 1). My question is how can I set resolution to 10hz? I increase the number of samples but from doing this only the frequency span changes and resolution remain same as 100hz. Resolution become 10hz only when I set total frequency span to 50 hz (but My frequency span of intrest is 0~500hz or 0~250hz not below thos).
I am attaching the gaph in attachment 2 from where you can undersatnd what type of resolution and frequency span I want.
Attachments:
fft graph2.JPG ‏39 KB
desired values for scales.JPG ‏35 KB

RE: date-time domain overhead in express queries.

DateTimeData objects in Forte are inefficient, both in terms of memory
footprint and instantiation speed. My understanding is that it stores
different parts of the date as separate textdata sub-objects.. Large
footprint also means they take a long time to pass across the network.
We rarely use DataTimeData or any related "domain" type objects. We have
our own date class which stores the entire date and time in a single string
attribute.. Much faster, much smaller footprint, etc. Fetches from the
database use a "to_char(...)" approach to format the date from the database
directly in to the internal string attribute in the correct format, again
for speed..
-Greg
-----Original Message-----
From: Jones, Kerreck [SMTP:[email protected]]
Sent: Tuesday, January 19, 1999 11:36 AM
To: '[email protected]'
Subject: date-time domain overhead in express queries.
In our application, we have an outline window which displays 11 fields, 3
of
which are date time domain.
Our database currently contains about 1500 entries, and the query takes as
long as 70 seconds. If we
remove the DTG domains from the application model, then the query takes
only
35 seconds. Is there any
known problem with the overhead of the express date time domain when doing
queries?
Thanks in advance for any info.
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/>-
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/>

I have considered this but have not found an elegant solution to the
problem of working accross multiple time-zones.
The application I am working on will ultimately need to work within Europe,
potentially servicing multiple time zones. By converting the date to a
string we lose the time-zone conversion that Forte does when an object
moves partitions and this is likely to cause problems as we then have no
"central" point of application time. If this is not a problem for you then
I would use strings as much as you possibly can.
If anyone has any thougths on how I could use scalar's in this case I'd be
interested to hear them. I've thought about forcing clients to "register"
with my central clock and then doing conversions behind the scenes but it
seems a bit inelegant.
However, one thing cannot be emphasised enough. Using the simple object
types (TextData's, IntegerData's etc) as class attributes is a really bad
idea, and will give you a number of performance penatlies.
Serialisation/De-serialisation of objects is really slow when compared with
scalars.
Scalars take up no 'object space' so you save on garbage collection.
Scalars are tiny when compared with their object equivalents.
Hope that helps.
From: [email protected]
To: [email protected]
Cc: [email protected]
Subject: RE: date-time domain overhead in express queries.
Date: 19 January 1999 18:22
DateTimeData objects in Forte are inefficient, both in terms of memory
footprint and instantiation speed. My understanding is that it stores
different parts of the date as separate textdata sub-objects.. Large
footprint also means they take a long time to pass across the network.
We rarely use DataTimeData or any related "domain" type objects. We have
our own date class which stores the entire date and time in a singlestring
attribute.. Much faster, much smaller footprint, etc. Fetches from the
database use a "to_char(...)" approach to format the date from thedatabase
directly in to the internal string attribute in the correct format, again
for speed..
-Greg
-----Original Message-----
From: Jones, Kerreck [SMTP:[email protected]]
Sent: Tuesday, January 19, 1999 11:36 AM
To: '[email protected]'
Subject: date-time domain overhead in express queries.
In our application, we have an outline window which displays 11 fields,
3
of
which are date time domain.
Our database currently contains about 1500 entries, and the query takesas
long as 70 seconds. If we
remove the DTG domains from the application model, then the query takes
only
35 seconds. Is there any
known problem with the overhead of the express date time domain whendoing
queries?
Thanks in advance for any info.
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive<URL:http://pinehurst.sageit.com/listarchive/>
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/>-
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/>

How Come on the zen xtra

How come on the zen xtra there is no "top 25 played" playslit or anything like that. i was recently playing around with a micro and i saw that there were playlist like that on the player. Can anyone answer that question for me?

I have been experiencing some extraordinary behavior with my Xtra. It seems to be deliberately choosing music for me based on genre, title info, even subject matter, when I randomize all tracks. This is no joke! The **bleep** thing knows my music better than I do, and some of the time it seems to be making fun, or even historical points, with some of my musical tracks. This could be a coincidence but with 5000 tracks representing every musical genre known it isn't likely. Could the firmware be capable of making these decisions based on track-tagging? I don't know. But it has made for some very interesting listening sessions.

How come I have to put in a keychain password every time safari or mail is opened? Is there a way I can disable it or save the password so it doesn't pop up every time?

How come I have to put in a keychain password every time safari or mail is opened? Is there a way I can disable it or save the password so it doesn't pop up every time? Also, I have my mail account set up from my Yahoo! account and every time I open mail, it asks for the password for my Yahoo! account. I have checked save this password to keychain and it persists on popping up repeatedly.

You don't want to disable keychain (if there's even a good way to do so), since it stores stuff like certificates and the such. It's quite useful.
Anyways, Keychains>Preferences>First Aid. Check Set Login Keychain as default. When you login, it unlocks the keychain.
That should help you.

In iPhoto 09 Info does not show tags on aperture, time, iso etc. Other tags like place, pixels are shown. There is no little arrow on this info menu to go to full info box. How come ?

in iPhoto 09 Info does not show tags on aperture, time, iso etc. Other tags like place, pixels are shown. There is no little arrow on this info menu to go to full info box. How come ?

It does. Photos Menu -> Show Extended Photo Information.
Then note the disclosure arrows as indictaed in this thread:
https://discussions.apple.com/message/16512794#16512794
Regards
TD

How does the abscissa change from time domain to frequence domain when running a FFT?

I'm working on a program about broadband ultrasonic attenuation(BUA) and met a problem with X-scale of the waveform after FFT. I used 'FFT Spectrum (Mag-Phase)' vi, but the order of magnitude of X-scale seems not resonable compared with reference. I decided to use 'Real FFT' vi instead and calculate X-scale by myself, but don't know how to change the X-scale form time domain to frequence domian while FFT. Thanks!

The VI 'FFT Spectrum (Mag-Phase).vi' will do the conversion for you correctly (following the formula given by Oleg), but only if you are providing the correct information about your sample rate, through the dt value (dt = 1 / Fsampling). If you only input your data array to the VI, it will "assume" you are sampling at 1 Hz, that is dt = 1.0 and your df will not be what you expect. So make sure you are using a Waveform Data Type, not a simple array. Use the Build Waveform primitive (located in your Waveform palette) to build a waveform with the correct dt value.

Frequency to time domain

Dear all,
I've acquired some frequency domain data from PXI-5660 using 'Read average power spectrum.vi' and 'SMT unit conversion'. Now, there is a requirement to convert this data into time domain. I've tried by simply passing this data through an inverse FFT VI but I didn't work. Any advices or suggestions on how I should proceed?
Thanks for the help!
Shazlan

Hi All,
I am working on DAC bench automation.I am sending a digital signal at some sampling frequency to DAC(Digital to analog) board.
The output from the DAC board is connected to Spectrum Analyzer(Agilent E4440A).
Using LabVIEW driver I am able to get the Frequency domain signal in my Graph.
I wanted to calculate the THD,THD+N,SFDR,Harmonics and SNR.Please anybody suggest how i can get these values.I am having below information:-
1. Sampling Frequency
2. The amplitude of the received signal is in dBm and base (X-Axis) is in frequency.
3. Fundamental Frequency.
4. Start Frequency and Stop Frequency.
5. There is the attached sampled data and snapshot of the frequency domain graph.
Thanks.
Ritesh Mishra
Attachments:
SampleFFTData.vi ‏16 KB
FreqDomainPlot.PNG ‏34 KB

My ipod nano was synced by itunes and removed all of my music and game files. I am in the process of adding my music back one cd at a time, but there is no history of tetris that I paid for from the itunes store. How can I get this game back for my ipod?

My ipod nano was synced by itunes and removed all of my music and game files, and replaced my music with my kids music that they have put into the current itunes library. My music is nowhere to be found on my computer, so now I am in the long, forever process of adding my music back one cd at a time, but there is no history of tetris that I paid for from the itunes store. How can I get this game back for my ipod?

Contact iTunes support and explain your situation to them. They may let you redownload it at no cost.
http://www.apple.com/support/itunes/contact.html
If they don't, I'm afraid you'll have to purchase it again. Sorry.
B-rock

How come in frequency/ Time domain there is no negative axis?

Similar Messages

Maybe you are looking for