Creating a real-time graph

Question

I'm starting out by collecting data from lab equipment that gives me intensity per wavelength.  There are 3648 data points that make up the wavelength range.  I know how to make a graph of Intensity on the Y axis and wavelength on the X axis.  What I need to do is isolate one wavelength data point and graph it's change in intensity over time.  I'm using the Extract Portion of Signal VI to isolate the correct wavelength and its corresponding intesity.  What I need to do now is graph the isolated intensity values over time.
I've tried showing this using a Chart VI and selecting Strip Chart in the Update Mode, but what keeps happening is the chart shows intensity on the Y axis and data points on the X axis.  I would like the chart to update live and show time on the X axis.  What am I doing wrong?

Answer 1

Trying to understand the problem... You have either a 2D array with wavelength values in one column and a second column with intensity (amplitude, absorbance, transmittance,...) values. Or, alternatively you have two 1D arrays containing respectively the wavelength and the intensities.
You know how to plot intensity against wavelength.
Your measurements are reproduced at various times, generating additionnal colums of amplitude data. You can plot these data on the same graph, generating a series of stacked plots.
And you want to select a given wavelength, retrieve and plot the intensities as a function of time (or measurement index).
If this is correct, could you give us a sample of your data ? 
Attached is an example, where a cursor is used to select a specific wavelength on the I = f(Lambda,t) graph, before plotting I = f(t) for this specific lambda.
Message Edité par chilly charly le 09-15-2008 06:16 PM
Chilly Charly    (aka CC)
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Attachments:
Select wavelength.png ‏46 KB
Select wavelength.vi.zip ‏39 KB