X-Y with intensity graph

Hello.
This is my task :
I have 2 waveforms with different frequency ( this is my output) I read them with Analog input. One waveform is x and the other is y. I have also the third input that is the intensity in every point ( so I have x,y and intensity). I need to built graph with these 3 parameters. Do you have any idea what kind of chart do I need?

I will try to explain my problem again.
I need to built raster with signal. In the analog output (two channels) I generate two waveforms with different frequency. With two Analog inputs I read this waveforms and also I read additional AI with signal intensity. And I need to present in the intensity chart or graph signal intensity in every pixel (x-y). So I need to solve a number of problems:
1. First of all I get tree AI in one waveform chart. And I didn't understand how I can split the signals from the different waveforms.
2. How to "explain" to the intensity graph that every point intensity has specific x and y.
Maybe now it is more clear. I attach my vi's maybe you can help me.
Thank you
Attachments:
AI+plot.vi ‏90 KB
AO.vi ‏63 KB

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Scaling intensity graph Z-ramp with panel - how?

In LV7.1.1 is there any way to get the color ramp associated with an intensity graph to scale with changes in the VI panel size?
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I think you are stuck.
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The only thing you could do as work around is to create a picture control (which size can be changed...) to mimick the graph scale...
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...

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,
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> 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

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.
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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
Solved!
Go to Solution.
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

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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

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Hi Hillary,
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Yes, I did tried to use Amplitude and Levels Express vi, it should be the one I am looking for, but I found it not work in my case, I need to put the value of amplitudes into a 2D array.
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How does LabVIEW Render the data in 2D Intensity Graphs?

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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

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Hi,
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Attachments:
export graph image.vi ‏406 KB

Seems the image indicator/clipboard method from the previous post has some limitations for larger sizes.
In this case, it works fine if you save to a file, e.g. as follows. (see attached 8x image). (No image container needed).
Message Edited by altenbach on 07-06-2009 04:54 AM
LabVIEW Champion . Do more with less code and in less time .
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export_graph_imageMOD2.vi ‏399 KB
8xsize.png ‏209 KB
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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

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not want to use IMAQ Vision is this particular application. Any
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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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Attachments:
test_color2.llb ‏2251 KB

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Attachments:
Bright spot.png ‏118 KB
block diagram.png ‏45 KB

Use "Array Max&Min" to find the peak coordinates, translate them to x and y values, and change your cursor position property node to write and write these values.
I am actually not sure why you have two cursors. A single cursor with a horizontal and vertical line seems sufficient.
LabVIEW Champion . Do more with less code and in less time .

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Howdy.
I have an Intensity Graph, with a 2D array of data (about 300x300) and a cursor. The cursor is locked to the plot, which for intensity graphs, means that the cursor is drawn at the lower left corner of the pixel that is being addressed.
Most of the time this works fine. However, sometimes, the cursor is drawn as being located at one pixel, but the values reported for the cursor are in fact a neighbor (usually the one to the right). The zoom level of the graph is such that a given pixel is larger than a screen pixel (about 3-5 times), so I wouldn't think that it was an aliasing problem, but the problem does go away if I zoom in a little further.
Has anyone else seen this? Does anyone have a fix?

I don't have a repeatable set of conditions that lead to this problem, so I don't have a demo vi that exhibits it.
As to unlocking the cursor, I think that in an intensity plot that is more confusing; the location and value reported for a cursor position are shifted half a pixel down and half left with respect to the way the plot is filled in. In other words, say we have a 10x10 plot shown in 100x100 pixel window. Each intensity value is 10 pixels wide. The axis values line up on the boundaries of these pixels. When the cursor is within half a unit (5 pixels) of the crossing point of these axes, that is, near the intersection of boundaries of four adjacent pixels, the value reported is the pixel location and value in the upper right of these four pixels. This means that with an unlocked cursor, I can be positioning it over (visually) the lower left pixel, but selecting the upper right. In fact 3/4 of any given pixel's visual representation is actually going to select some other pixel. So I've locked the cursor to remove that uncertainty; now it is supposed to be always in the lower left corner of the pixel selected.

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

X-Y with intensity graph

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