Using intensity graph

Hi,
Currently, I have some problem using the intensity graphs. I am using the Time frequency toolbox in Labview. Currently, I am having a problem where I needed to plot the spectrogram of the signal. I have tried to maintain a plot of spectrogram at 0 to 4s and another at 4s to 8s. I am trying hard to plot two graph together, to form a plot of 0s to 8s, in the spectrogram. Furthermore, the time axis will continue to increases at 4s interval with updated spectrogram. I wonder how could i achieved in having two spectrogram with two different time interval to display a common plot? Thanks a lot for advice.
Rdgs
kengkc
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Hi kengkc,
Correct me if I am wrong, but are you saying that you have the data for the first 4 seconds of your acquisition (t = 0 to 4) and the next 4 seconds of your acquisition (t = 4 to 8) and you want to combine them into one plot? I presume since you were able to plot them in an intensity graph to begin with, that they are already in arrays.
If that is what you want to do, you can easily concatenate your arrays using the Build Array function (this means to append one array to the end of another). Add your Build Array function from the Array subpalette, and make sure you right click it and choose Concatenate Arrays so that you dont get more dimensions in your resultant array. Then expand the Build Array function so that you can wire your arrays into it.
Please refer to the attached screenshot for an idea of what I mean.
Hope this helps.
Best regards,
Vern Yew
Applications Engineer
Attachments:
concatenate.JPG ‏17 KB

Similar Messages

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
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appreciated. Thanks.
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[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 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
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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,
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Single pixel formation in Intensity graph

I needed to capture a image using CCD camera. Though it has 16 bit resolution, i need to focus on ONE PIXEL.
The process goes like this. Save the image information in a spread sheet array and then find the max value of the array. Till this step, i am OK.
But how do i get to display this MAX value using intensity graph??
Intensity graph is 2D array which needs X and Y value.
So I need to get the X and Y value of the max value of array. I tried using the max index value of 'Max and Min' array function. But it is of no use since the value comes as 1Dimension but the intensity graph needs 2D information in the form of X and Y value.
Please help me on this. Thanks in advance.

Asking the same question in multiple threads does not help or get you an answer more quickly. Please be patient. Many of us who participate in the Forum do so as volunteers.
Now to your question. As you noted, you can use the Array Max & Min function to locate a pixel with the maximum value. If more than one pixel has that value, this function only reports the first occurrence of that value. The 1D output of the Array Max & Min function contains the indexes of the pixel. So the first element would be the row index (X value) and the second element would be the column index (Y value). What I do not understand is why you want to display just one value on an intensity graph. That seems rather meaningless. Please explain what you want the output to look like.
Lynn

Intensity Graph control using VC++ 6.0?

LabView supports an "Intensity Graph" control. Is there a way to accomplish the same thing with CNiGraph, CWGraph or CNiGraph3D?

Thank you for you answer. It was very helpful. One thing missing is the "intensity slider" that is part of the LabView control. It allows the user to adjust the image display. The other problem I have is that the 3D graph axes labelling always looks big and clunky no matter what I use for font type/size. What I am trying to emulate is shown in the attachment. Basically I am translating some LabView code into C++.
Attachments:
Image1.bmp ‏203 KB

Image processing from .txt file onto an intensity graph

I am doing a mini project in my class and I was wondering if anyone could help me. It about image processing but I am bit stuck.
Heres the idea:
"An image is really nothing more than a 2D array of data. The value of every element in the array corresponds to the brightness of the image at that point.
In this project you will create a VI which loads a 2D array of data and then displays it on the screen using the Intensity Graph. Three example files (boats.txt, gordon.txt and parrot.txt) are available on the module webpage that you can use. However, you can also use any other black and white image you like, but will need to convert it to a “text image” first. To do this you can use some software called “ImageJ” which is available on the computers and is free to download.
You can vary the brightness of an image by adding the same value to every element in the array.
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Some other ideas that you could try with image manipulation are:
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First I am having problems putting my picture onto the graph. It is in the write file but the colours are not correct and the image has rotated 90 degrees. I will upload my VI so far when I get back onto my computer.
Would really appricate the help! Thank you for reading

Hi charlthedancer,
Here is an example to get you started.
Kind regards,
GajanS
Attachments:
Test.vi ‏14 KB

Programmatically disabling/enabling cursor in intensity graph

Hello all,
I am building a LV interface (LV2011) for a stepper XY stage. The system "scans" a surface, displaying it on the graph. I set up to cursors to zoom into a region of interest (ROI). Pressing a button resizes the scales to the ROI (zooming in on the area). Sections of code move the XY stage, and read a device. When done I want to zoom into a ROI and use a THIRD cursor to manually move the XY stage. I have this working with TWO graphs, based on the "region of interest.vi" I found in the dev zone.
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Thanks,
Steve
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Attachments:
roi.llb ‏40 KB

Your exmaple works perfect. Howver I am having probs with Val(sngl) on the XY graph. On the example you gave, lets say I move the cursor with the mouse - event fires, everyone is happy. If I move the cursor with CODE - nada. I even read the "Value" of the graph and wrote it to "Val(sngl)" to try to fire the event. How does one force a trigger on an XY chart when you move a cursor (say cursor idx2) using code?
Better yet - why when I read the Val and write to Val(sngl) does the event not fire??? I have been searching for a basic XY table with sensor -type project but havent found one yet. Everyting works great - draginng the cursor moves the XY stage. Now I need to do the auto-scan part Use code to place the cursor - trigger the even that moves the stage.
Thanks
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Attachments:
XY_Stage_Rev8.vi ‏53 KB

Change colors of individual pixels on intensity graph?

I would like to be able to change the color of a set of individual pixels within an intensity graph, to blue for example, while leaving the color table otherwise as is, for example, gray scale. The change to blue would be based on location, not on current gray value. I think I can accomplish this using the mask fx with picture controls, and then convert to intensity graph. Is there a more direct way? A good example to demonstrate this capability would be just using a 'mouse down' event on an intensity graph to change the color at the mouse location. Any thoughts are appreciated.
Sincerely,
Don

Yes, seems to work fine .
If you have LabVIEW 8.0, there is another possibility. There is a new property that allows drawing any pictures or picture elements on your graph area. Of course you could draw individual pixels, but nothing prevents you from e.g. drawing circles, squares, odd shaped areas, arrows or event text. ... Anything you could do with a plain picture indicator. One example that ships with LabVIEW 8.0 is Envelope.vi, see image.
Message Edited by altenbach on 06-12-2006 07:31 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
envelope.png ‏32 KB

Most efficient way to extract the amplitude of a signal and display on an intensity graph

Hi All,
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Hi Hillary,
Thanks for your reply.
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Cannot make vertical axis of intensity graph logarithmic

Has anyone else noticed that that the vertical axis on intensity charts cannot be made logarithmic? Labview gives you the option, but doesn't do anything when you try and check the box. Property nodes don't seem to work either. Tried this in LabVIEW 2011 SP1 and 2013. Am I doing something wrong or is this just a feature that isn't avaiable? I am just wondering if its my install or something that is really an issue.
My application is to plot the power spectrum of sound on a intensity chart to show history of sound recorded by a microphone in real time. Really good to pin point source frequencies of feedback.
Amit

Hi Amit,
This is a documented problem with LabVIEW and it is currently being worked on. Here are a couple other Forums that discuss it and offer workarounds for this issue.
Log scale in an Intensity graph
Possible bug in Intensity Graph while using interpolate colors on a Log scale
Intensity Graph - Mapping Mode
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National Instruments

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.
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Sincerely,
Don
Attachments:
test_color2.llb ‏2251 KB

Setting intensity graph to blinking causes LV2012 to crash

Hi,
This VI crashes when setting blinking to TRUE, using LV2012, Win7 32 bit. I saw that this was a bug in 2004 , hasn't it been fixed yet? Or am I missing something obvious?
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"Wisdom comes from experience. Experience is often a result of lack of wisdom.”
― Terry Pratchett
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Attachments:
testBlinking.vi ‏16 KB

Yup, still broken LV2013SP1.
I'm not making any excuses for non-action, but I would image that blinking an intensity graph isn't something they get a lot of complaints about...
Mike...
Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion
"... after all, He's not a tame lion..."
Be thinking ahead and mark your dance card for NI Week 2015 now: TS 6139 - Object Oriented First Steps

Fix axes in intensity graph with cursor

Hi all,
I try to use the intensity graph as an xy-input device. The user should be allowed to drag the cursor to enter the value. However, the user can always move the cursor outside the plot area, which causes the corresponding axis to rescale. I want to have strictly fixed upper and lower limits. Is there any way to achieve this? One possible solution would be to reset the min/max values every time the cursor was moved (and coerce the cursor position back into the range). A simpler approach would be appreciated!
Regards,
Matthias

> I try to use the intensity graph as an xy-input device. The user
> should be allowed to drag the cursor to enter the value. However, the
> user can always move the cursor outside the plot area, which causes
> the corresponding axis to rescale. I want to have strictly fixed upper
> and lower limits. Is there any way to achieve this? One possible
> solution would be to reset the min/max values every time the cursor
> was moved (and coerce the cursor position back into the range). A
> simpler approach would be appreciated!
>
You don't say what version of LV you are using, but if it is relatively
recent, right click on the graph and go to Advanced and uncheck the
option to have Cursors Scroll Graph. The user can still drag and
release the cursor und
er the edge of the graph, but this will not change
the scales. You can pretty easily filter cursor points that are out of
range and even write back to the cursor value if you need to. I believe
that if there is data in the plot and the cursor is set to lock to the
plot, then it cannot be dragged outside the data either, and that is
another solution.
Greg McKaskle

Merge a intensity graph to a Serial write/read

Hey.
I am doing my bachelor in Labview, and are using a arduino 2560 as a microcontroller for a thermal sensor.
After many attempts on connecting the arduino to labview using LIFA.BASE I get connection sometimes, and sometimes not.
I tried the Serial write and read program on the forum, and got much better reliability.
I would like to use VISA, instead of Arduino int.vi
I was hoping I could change the Serial write and read(removing the string) with putting an intensity graph in it?
I have added the bachelor program along with the Serial write and read, can someone please help me??
Attachments:
bachelor_2013.vi ‏259 KB
Modded Advanced Serial Write and Read_test.vi ‏40 KB

There is the Simple Serial Write Read example. That should get you started with talking over a serial port with VISA.
It seems like you have an array of bytes that you need to send. You just use the Byte Array To String to convert directly into a string and send it. For reading, there is the String To Byte Array that you can use to start parsing your data.
Show us what you have so far. Be sure to include any sample data you may have and expected results. Things get really confusing when stating ASCII and Hex since people can interpret that in 10 different ways.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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Control grid intensity graph

Hi,
I want to control the grid of an intensity graph to be exactly spaced by "1"... How to do?
See attached example in LV8.5. Start with default values and you get grid lines with spacing of 1.
Now change "size" to 15 and run again. Gridlines are now spaced by 0.5. Size=10 -> spacing of 0.2, size=4 -> spacing=0.1 ...
I want to have a spacing of 1 regardless of size parameter! How to achieve this?
Btw. I need both major and minor grid, as array size can grow to more than can be handled by major grid alone...
Message Edited by GerdW on 02-26-2008 03:09 PM
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome
Attachments:
Test_Grid_LV85.vi ‏16 KB

Hi Simon,
thanks for clarification.
To summarize: major increment has to be bigger than minor and you have to set them both...
Scale labelling is not so important for me, but it would be nice to have each number when space is sufficient (in the example vi for sizes upto 15). It seems I have to change my graph formatting a little bit: make minor grid transparent when not needed (for small sizes) and switch gridlines on, when scale space is not sufficient to show all numbers...
In the attached example pic (today's measurement of pressure sensor wafer ) I use the gridlines to separate single chips. And I always want to separate single chips regardless of array size (=wafer/chip) - which can vary from 10 to ~80...
Message Edited by GerdW on 02-26-2008 05:26 PM
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome
Attachments:
grid-example.png ‏27 KB

Using intensity graph

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