Programaticaly changing Histogram properties

[Jan50]

Hi,

I want to change # bins and Max and Min value of the Histogram vi. programaticaly

Other vi's have property nodes which can be used but can't seem to find them for Histogram vi (express / signal analysis)

I can of course make my own histogram application with an X Y graph but that would require some programming.

I must be overlooking something,  Can't believe NI guy's forgot to put in the option.

Jan

[MikeS81]

Hi Jan50,

do you mean this vi? Which min and max value do you want to change?

Mike

[Jan50]

Mike,  Thanks for your answer. You did point me in a new direction but have not yet been able to solve the problem.

First, what I want to do is create a histogram of a number of measurements. Each measurement creates one scalar. Every time a measurement is done I want to see the histogram grow. I have done this using the schematic attached (top half).  I store a single scalar in to an array and feed the array to the histogram vi after converting it to dynamic data. Before the next measurement I clear the array. All is done in sequence using a state machine.  This works ok  but I can only change the min max and bin values in the dialog box of the histogram vi. (no property nodes)

The other histogram vi you suggested does have the property nodes to programmatically make changes but I can not make it update after every test.  It seems to reset when I write the next value.

An other problem is that I can not use my old graph vi with the histogram vi you suggested. The first one wants dynamic data and the second a cluster. Trying to convert didn’t work. (see picture)  All my other graphs have a black background with grid and the orange one looks a bit out of style.

Question: How do I make a histogram update after every sample, see the result on a black-grid graph and programmatically change the min, max and bins of both the histogram and graph vi.

Cheers,

Jan

[Karunya_R]

Hi Jan,

There is an example at C:\Program Files\National Instruments\LabVIEW 8.5\examples\analysis\statxmpl.llb called running histogram.vi. This example has two graphs, one for the gaussian noise and another for the histogram and it also updates the histogram as the data is updated. It has a control to change the number of bins for this. The General histogram.vi has inputs for max, min and bins. You might want to check if that fits your needs better.