MATLAB pcolor and LABVIEW Intensity Graph

Hello all
I have a data matrix which i want to plot using intensity graph of LABVIEW. My problem is that when i plot this matrix using MATLAB pcolor along with "shading interp" command, i got a very fine and smooth coloring graph of this matrix, however, using LABVIEW Intensity graph along with getcolor vi, i was not able to get a smooth coloring graph comparable to MATLAB pcolor. I have tried many setting but results were not satisfactory
Is this due to a limitation of LABVIEW intensity graph or i am missing something? Kindly help me
Best Regards
Asim

Thanks for providing that Asim, unfortunately the VI you provided is unusable as-is. There is a subVI missing, and while not critical, it's difficult to tell how you're setting up the intensity graph without that VI. Additionally, it doesn't appear that there is any graph data included in the VI you provided and a third-party software license would be required to use this VI. Could you upload the data you're handling in a format that works without any external tools?
As for thoughts on the differences in the plots; they are largely similar in appearance, although it does appear that you're using a different color scale in LabVIEW- the majority of your scale is in the blue-green range, rather than continuing linearly through yellow, orange, and red. You're going to lose a lot of visual resolution in the ranges you're highlighting due to this. The plot you're trying to achieve also appears to be interpolated or blurred around the edges of bins, are you actually plotting data between integers on the x-axis, or is this an artefact introduced by the software?
Regards,
Tom L.

Similar Messages

Labview Intensity Graph Vertical Axis Label

When I change the font of the vertical axis label of a Labview intensity graph, the label disappears. Is this a Labview bug or is there a way to correct the problem?

Here are those screenshots... I was a little quick to submit
- JLS
PS - of course, when you're editing the free label, it doesn't have those nasty affects, and if you group the objects (see the Free Label and Grouping screenshot) it behaves (at least cosmetically) much like a native graph label
Best,
JLS
Sixclear
Attachments:
Free Label and Grouping.JPG ‏81 KB
While Typing.JPG ‏66 KB
After Typing and Clicking Off the Graph.JPG ‏67 KB

Relations between Matlab structures and LabVIEW clusters

I have a DLL created with Mathworks COM Builder, used as an ActiveX component in LabVIEW. Thus, I am able to have my Matlab functions inside LabVIEW. However, I have a problem regarding the pass of parameters between Matlab and LabVIEW.
When the Matlab functions parameters are simple -DBL, DBL arrays, strings-, there is no problem. LabVIEW does the right translation. But I have not been able to pass a Matlab structure to LabVIEW, which counterpart I think it would have to be a cluster. To solve this situation I need to split the structure components and pass them separately.
Does anyone know how to do it without the workaround?
Thanks in advance and have a good day,
spj

Hello Tishu,
1)       Can we use nested for loop in Mathscript node?
1) Yes you can. Remember that loops should be avoided as much as possible in m-scrips. Most of the times you can use vectorization to represent same task.
2)       Which one of these is feasible: 1) Matlab script node
                                                          2) Mathscript node
2) What exactly is the "Feasable" question? Real time (see below) or nested loops (see above)
      3) Is there any other way to interface between matlab and LV for real time signal processing?
3) Real time is different depending the application. Some applications need ns or ps real time (RF appls) others need seconds delay. Real time means "determinism". That a task will execute in a know time with little jitter. Windows is not a real time OS therefore nothing in it will operate in real time. Can you tell us something about the signal your are processing (Audio, Image fps, Radar)?
     4) Suppose X is 1D array (DBL) in Labview. And Mathscript code is as below:
For i=1:inf, 4) Is this vector a valid one? inf = Inf which is different from 1/eps.
Y= X-1;
end
Here X is input and Y is output.
Such code does not produce output (Y variable) in real time processing.
Does it wait till the FOR LOOP ends? Is there any solution to such problem? 5) What is this suppose to produce?
Let me know,
yardov
Gerardo O.
RF Systems Engineering
National Instruments

Matlab int16 and labview int16

I used labview 7.0 to create a int16 binary file by the "Write to I16 file.vi". When I try to read this file as int16 type in Matlab 7.0, it seems like the value was timed by a factor of 256. For example, a value of 5 in labview int16 file would become 5x256=1280 in matlab. The problem now is if the data value in labview int16 file is greater than 128, than the data value in matlab would exceed 128*256=32768. Do I need to do any data type change before reading this file in matlab?
Thanks a bunch!
Julian

Big Endian vs Little Endian. Use the 'Swap Bytes' function (Advanced pallette>>Data Manipulation).
0x0005=0d0005 is being read as 0x0500=0d1280
and you may want to take a look at Writing Binary Files with LabVIEW That Can Be Read by Other ApplicationsMessage Edited by Donald on 04-25-2005 03:11 PM
=====================================================
Fading out. " ... J. Arthur Rank on gong."

Cursor/Window for Zooming in Intensity Graph

Does anybody know how to create a non-rectangular window (any shape
connected by mouse clicks) for zooming (or for data retrieval) if a
particular area in the graph is of interest in a intensity graph?
Wouldn't it be really cool if we can select edges in a graph and
retrieve the information (or data) from the graph?
The other question of mine is: is there a way that when we're using
intensity graphs, we can create the custom menu with right mouse button
click, instead of the standard set of menu items? Any help is greatly
appreciated. Thanks.
Sent via Deja.com http://www.deja.com/
Before you buy.

[email protected] wrote:
> Does anybody know how to create a non-rectangular window (any shape
> connected by mouse clicks) for zooming (or for data retrieval) if a
> particular area in the graph is of interest in a intensity graph?
> Wouldn't it be really cool if we can select edges in a graph and
> retrieve the information (or data) from the graph?
In my pre-NI days, I had a lot of fun trying to coax image-manipulation and
-analysis behavior out of LabVIEW intensity graphs. You can do a fair
amount by making use of cursors and hotkeys and creating pseudo-overlays by
setting image coordinates to certain colors to create visual cues in
response to user inputs.
That being said, I never considered trying to get complex ROI (region of
interest) info from a user wi
th an intensity graph, and I'll bet it's a
pretty tough GUI trick unless you're using IMAQ Vision. If you find
yourself trying to build features like this into your application, or doing
a lot of image manipulation in general, you might save yourself time in the
long run by getting the IMAQ Vision toolkit from NI.
> The other question of mine is: is there a way that when we're using
> intensity graphs, we can create the custom menu with right mouse button
> click, instead of the standard set of menu items? Any help is greatly
> appreciated. Thanks.
I'm not aware of a way to suppress the built-in context-sensitive popup
menus. Sorry!
Regards,
John Lum
National Instruments

Matlab routine within labview cannot get input after a few hours of use. What can be the trouble?

I have a Matlab-within-Labview application that needs to run 30-40 times in a row. However after let's say 10 runs I get error 1047, that is, there is no communication between Matlab and Labview. I have to reset the computer to start re-running the application without problem. Note that Matlab is open on this computer all the time.

Hello,
The only information I could find on this from NI or MWorks is that MATLab must be running in order for LabVIEW to access the Matlab server. I would check to see if there is anything specific happening inbetween the 10 and 11th runs that causes the link between the Matlab server and LabVIEW to break, isolate where this happens and try to work from there.
Doug

How does LabVIEW Render the data in 2D Intensity Graphs?

Hello,
I was hoping someone could explain to me how LabVIEW renders it's 2D intensity data. For instance, in the attachment I have included an image that I get from LabVIEW's intensity graph. The array that went into the intensity graph is 90000x896 and the width/height of the image in pixels is 1056x636.
Something I know from zooming in on these images as well as viewing the data in other programs (e.g. Matlab) is that LabVIEW is not simply decimating the data, it is doing something more intelligent. Some of our 90000 lines have great signal to noise, but a lot of them do not. If LabVIEW was simply decimating then our image would be primarily black but instead there are very obvious features we can track.
The reason I am asking is we are trying to do a "Live Acquistion" type program. I know that updating the intensity graph and forcing LabVIEW to choose how to render our data gives us a huge performance hit. We are already doing some processing of the data and if we can be intelligent and help LabVIEW out so that it doesn't have to figure out how to render everything and we still can get the gorgeous images that LabVIEW generates then that would be great!
Any help would be appreciated! Thanks in advance!
Attachments:
Weld.jpg ‏139 KB

Hi Cole,
Thank you for your understanding. I do have a few tips and tricks you may find helpful, though as I mentioned in my previous post - optimization for images or image-like data types (e.g. 2D array of numbers) may best be discussed in the Machine Vision Forum. That forum is monitored by our vision team (this one is not) who may have more input.
Here are some things to try:
Try adjusting the VI's priority (File»VI Properties»Category: Execution»Change Priority to "time critical priority")
Make sure Synchronous Display is diasbled on your indicators (right-click indicator»Advanced»Synchronous Display)
Try some benchmarking to see where the most time is being taken in your code so you can focus on optimizing that (download evaluation of our Desktop Execution Trace Toolkit)
Try putting an array constant into your graph and looping updates on your Front Panel as if you were viewing real-time data. What is the performance of this? Any better?
The first few tips there come from some larger sets of general performance improvement tips that we have online, which are located at the following links:
Tips and Tricks to Speed NI LabVIEW Performance
How Can I Improve Performance in a Front Panel with Many Controls and Indicators?
Beyond that, I'd need to take a look at your code to see if there's anything we can make changes to. Are you able to post your VI here?
Regards,
Chris E.
Applications Engineer
National Instruments
http://www.ni.com/support

Same code gives different results in Matlab Script in Labview and Matlab

I am implemeting a Matlab code into a LabVIEW application using Matlab script. When I import the exactly same code to the Matlab Script in LabVIEW it gives a different result than it is in Matlab. This code is a simulation code including first kind bessel functions. Using LabVIEW 7.1 and Matlab R14 service pack 3.

Labview 8.5
Matlab R2009b
Attached are the graphs produced by matlab script in labview and in matlab.
The minimum of graph produced by matlab code is below 1 and that in labview is above 1.
Thanks a lot for your reply.
Sorry, I haven't quantified the "sometimes" yet.
Attachments:
matlabsResult.jpg ‏29 KB
LV.png ‏84 KB

BCG Brightness Contrast Gamma - Looking for BCG function returning color table / lookup table coded in pure G and applicable to Intensity Graph or Picture Control

Looking for BCG function returning color table / lookup table coded in
pure G and applicable to 8-bit Intensity Graph or Picture Control. Do
not want to use IMAQ Vision is this particular application. Any
help is appreciated.
Sincerely,
Don

Take a look at this color model software I put together. (Don't concern yourself much with the basic programming at this point.). The color component generator subVI is borrowed from a LabVIEW example.
First look at test_color2.vi. If you adjust the sliders of the various controls, you will see how it works. You can see that for pure B&W images, brightness, contrast, and gamma (which I think I have coded correctly) are all fairly straightforward to modify.
Now look at test_color3.vi. Here we try to adjust BCG for color images using the color model shown here where current color component clusters are carried into the BCG event cases via shift registers. You can see that once color is introduced into the image, it becomes difficult to mix the colorizing with the BCG model. And this is pretty much where I am right now.
Would be interested in comments / suggestions.
Sincerely,
Don
Attachments:
test_color2.llb ‏2251 KB

LabView crash when intensity graph is in P6 of tab control

Any available fixes for LabView crash when intensity graph is put on page 6 of tab control and right-clicked??

Michael,
This has been fixed in LabVIEW 6.1.
Regards,
Cyril Bouton
Applications Engineer
National Instruments
Cyril Bouton
Active LabVIEW Developper

I want to select a specific rectangular position from intensity graph to extract the x and y values

I want to select specfic rectangular postion from an intensity graph to extract the X and Y values at that specific position.
Is this possible using LabVIEW?
@nk

Hi nk,
Is this possible using LabVIEW?
Yes.
I want to select specfic rectangular postion from an intensity graph to extract the X and Y values at that specific position.
Just select the positions! What's your problem in doing so?
Btw. when you select positions you already know their XY values!? I don't get the point of your task...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Recording Zoom factor and Pan position for intensity graph (LV8.2/8.5)

I'm using the zoom and pan features on the graph palette. I need a way to determine the zoom factor and pan position so as to reapply these to another intensity graph. Any way to do this?
Thanks,
Don

Can't you just copy over the Xscale.range.min|max and yscale.range.max|min?
LabVIEW Champion . Do more with less code and in less time .

Labview Intensity Charting/Graphing

How do you get an array with three columns of data to be 3 individual arrays and then graph them in an intensity graph/chart? I am pulling data from tcp and it is output as a comma separated string and a carraige return to denote an end of variables so the output in the data stream looks like:
(X,Y,Intensity)
6,80,9,
74,14,0,
51,69,1,
then i conver it to s spreadsheet style 2D array. I talked to the labview reps and they said I need to use something like Replace Array Subset. To do this. I have included the VI and an image of what my current setup results in. Basically I just want the intensity to be plot at the X and Y coordinate specified in the set. Thanks!
Attachments:
TCPGraphing.vi ‏40 KB
labview.png ‏108 KB

If I understand correctly, you will want to initialize a 2D array of the correct size for your data filled with zeros. As the data is read in, use the Replace Array Subset to replace a zero with the new data. The X and Y coordinates will determine which element of the 2D array to replace with the associated Z value. Something like the attached maybe?
Randall Pursley
Attachments:
Replace.png ‏20 KB

I have a problem with simulation in Matlab 6.5 and LabVIEW for PID controllers

I have a problem with simulation in Matlab 6.5 and LabVIEW. I have some methods for granting PID controllers in MATLAB to go but not LabVIEW. International Teams degree to transfer two but when I go past the fourth degree no longer work. We changed the formula for calculating the parameters for grade four and gave me some good values for Matlab award but when I put on LabVIEW have not settled. formulas are available in PDF and are. Please help me and me someone if possible. Thanks
lim.4 generation parameters in MATLAB program and comparison methods are for second-degree transfer function.
Solved!
Go to Solution.
Attachments:
Pt net.zip ‏2183 KB

This is the VIs what i try to make,but is not work. This pdf. document was used to create last VIs PID. thenk you for your colaboration.
Attachments:
PID create by me.vi ‏312 KB
tut_3782.pdf ‏75 KB

MATLAB and LabVIEW Communication Optimal Performance

I have tried my own code, searched through forums and examples to try and figure out best method to communicate between LabVIEW and MATLAB. Most of the information I found was over a year old and I was wondering if there was a better current solution. My goal is to work in LabVIEW to collect the data, process in MATLAB and return the results to LabVIEW. I have encountered some difficulty in my search and before I delve even further in to one in particular, I was wondering if anybody had an optimal solution with this communication protocol or solutions to my errors encountered thus far.
I have looked at the following methods.
1)TCP/IP and a very good example found here: http://www.mathworks.com/matlabcentral/fileexchange/11802-matlab-tcp-ip-code-example
When I try to adjust even the example and communicate for my own purposes I get the following errors
Error 63 if MATLAB server not running
Error 66 occurs if the TCP/IP connection is closed by the peer. In this case, Windows notices that no data is returned within a reasonable time, and it closes the TCP/IP connection. When LabVIEW attempts to communicate after Windows closes the connection, error 66 is the result.
However, the example itself works perfectly and does not get these errors
2)Math Script Node, works but the post below states that MATLAB Node is faster.
"computing fft of a 1024x1024 matrix ten times (attached code). Result is that Matlab node version takes 0.5s versus 1.6s for Mathscript node version."
http://forums.ni.com/t5/LabVIEW/Why-are-mathscript-performances-much-below-matlab-s/m-p/2369760/high...
3) MATLAB Node, which states it uses ActiveX Technology seemingly works well, but loses time for data transfer.
4) Trying to use the ActiveX functions or if there is other Automation potential.
5)Other solutions that I have not found that might be better suited.
Thank you for any help or suggestions in advance.

Barp and Mikeporter,
Thank you for your assistance:
The reason I need to do the processing in matlab is as you mentioned the processing script is coming from another person who has already developed it in matlab. I almost have to treat it as a black box.
The TCP/IP method was interesting is that none of the errors show up when I run the example but if I try to modify it in a new VI I get the errors.
I have attached a simple program that just has a basic butterworth low pass filter I am trying to confirm if it works in the Matlab node. I have done other simple codes which work, and this one does not seem the implement the appropriate filter. The LabVIEW signal and LabVIEW filter seem to work at the default values (but not if I change sampling rate) for the Simulation of signal, Matlab signal and Matlab filter work, but the Labview signal processed in Matlab is not working...
Ideally it would be bandpass filtered (0.1-30) at sampling rate of 256 Hz and further processed from there, but I can't even seem to get low pass to work in the matlab to labview communication.
Any help would be greatly appreciated. Once I have that working I will have more of an idea of the constraints of the actual processing Matlab Code I will be using.
Thank you again.
-cj18
Attachments:
labview_matlab_filter.vi ‏70 KB

MATLAB pcolor and LABVIEW Intensity Graph

Similar Messages

Maybe you are looking for