LabVIEW PDA Interpolate 1D Array

[Martin_Manger]

Hello,

I have a set of 128 datapoints (with x and y coordinates) which I want to interpolate to 400 datapoints. For this I use the "Interpolate 1D Array" function. If I run this VI on a Win2000, everything is fine. But when I try to run the VI on a PDA with PocketPC2003, I get only pointless values. Someone an idea what I made wrong?

Thanks, Martin

[Matthew C]

Martin,

Thank you for contacting National Instruments.

Try running a similar program on your PDA that uses the same interpolation VI, but instead of grouping together points inside of a cluster, pass a single array of numbers into the Interpolate 1D Array function. I am interested in seeing if it will work correctly with just an array of numbers.

Let me know how this goes.

Matthew C
Applications Engineer
National Instruments

[Martin_Manger]

Hi,

Thank you for your answer. Using a single array of numbers works correctly on PDA. But I need to interpolate the points by the following way:
I have some datapoints like (379,23; 7580),(384,51; 9210), and I want to interpolate the y-values for the corresponding x-values 380, 381, 382 and so on. So I have to use a cluster with this function.
Any idea why it works with an array, but not with a cluster?

Martin

[Matthew C]

Martin,

I apologize for the delayed response.

Try using two array constants in your VI rather than two array controls. See if that does the trick.

Arrays are among the number of front panel objects that are not supported in the PDA module. While you can still build VIs that use arrays, I suspect that your array controls are not retaining their data when you download the application to the PDA.

I have a feeling this may resolve the problem.

Matthew C
Applications Engineer
National Instruments

[Martin_Manger]

Hello Matthew,

I think I've found the problem. The "Interpolate 1D Array" function expects an array of double precision numbers, but I've connected an array of single precision. On PC's it seems to be converted by the function. On a PDA I have to convert the array to double precision by using a number conversion function before connecting the array to the interpolate function. Then it works also with array controls which are not displayed on PDA's but I can use as connectors in SubVI's.

Nevertheless thanks for your effort to solve the problem.

Martin