Pixel to mm

I don't quite understand the purpose of that function and what b and fx represent, but if you want to scale image pixels to mm you can simple use SetScale:

I'm not quite clear what you want to do. I think the reason you get 0 is that you are making a wave called fx and nothing is in that wave.

There's two different ways you could do this and as I see it you are trying to both in your code. One way is that you have a wave that has discrete values for numbers of pixels (where let's say each row - p - relates to different images or different measurements). You can convert those values by dividing each point in that wave by a (not multiplying as you have written). The second way is that you have a wave which corresponds to values found at pixel locations. Here you'd want to scale each x value to be the correct distance. This means you can access values by referring to their x-value (in mm) rather than their point value (p).

Take a look in the help topics - find out what p and x represent in a wave. Then try and edit your code and ask another question if it's not clear.

Thanks for the help. I fixed it.

For future forum readers, please post your fix.

This is also a traditional courtesy to those who have taken time to help you.

Thanks!