Analyzing Graph Data

[Mike415]

Hi,

I'm trying to make an equation that will be able to get the peak Y values from two peaks on a graph and find the difference in these values.  The attached image might clarify it a bit more.  The best solution would be something that actually found the peak values and then gave the difference, but for now I think using the Y values from the cursor legend will be sufficient.  For this example, what I would be looking for is basically the 208 - 189= # Displayed somewhere

Is this possible with LabVIEW?

Thanks,
Mike

[MikeS81]

Hi Mike,

why are the marked points are values you want to find, but the first one with a value of 420 not?

Mike

Message Edited by MikeS81 on 07-29-2008 08:43 AM

[Mike415]

I don't really understand what you are trying to ask, but I'm just trying to get LabVIEW to display the difference in the Y Values for you and maybe in the future get it to actually find the peaks.

Thanks

[MikeS81]

Hi Mike,

use a property node. First select the active cursor and then read the Cursor -> CursorPosition -> Cursor Y value. You can do it in a for loop.

Mike

[Mike415]

Thanks,

But the problem is now I cant get it to give the value of the first cursor.  It only gives the value of the second cursor for both property nodes.  I tried selecting each one in the cursor legend prior to making the node, but it didn't make a difference. ill keep trying different things.

Mike


Message Edited by Mike415 on 07-29-2008 10:28 AM

[MikeS81]

Hi Mike,
connect a "0" for the first plot and a "1" for the second. If you do it in a for loop you can directly connect the iteration counter "i". Connect the result (the y value of your cursor) to the for loop. You have by default autoindexing so that you get an array. Use the index array function, resize it to two outputs and use the subtract function to get your result.

Hope it helps.
Mike

[Mike415]

This is where I am at and I'm sure its way off.  I really appreciate this.  I don't know whether to use one for loop, or one for each, or just one for the equation etc.  Ive been stumbling around on this all morning.

Thanks

[MikeS81]

Hi Mike,
see the picture, it shows how to do it.
Mike

[Mike415]

It worked!

Thanks so much