DPlot

I am creating vector plots and several other types of plots of experimental data. I have data that is not complete, there are missing data points because of the experimental technique. For example, I am plotting velocity vectors on a 75x25 grid, but I do not have data (or the data point is zero) for some of the grid points.

How can I handle this in DPlot?

In some cases I would liketo simply not plot the missing data points.
In other cases, I would like to interpolate to fill in the missing data point.

Any suggestions will be greatly appreciated!
Thanks,
Frank

How can I handle this in DPlot?

I'm not sure I understand what you're trying to do. If you're working with a vector plot then DPlot needs an X,Y,magnitude and direction. If you're saying that you DO have a Y coordinate for some particular point but do NOT have the vector magnitude and/or direction - DPlot will not handle that correctly. All you can do is edit your data so that you have all 3 (or do not have any) of Y,magnitude,direction at that point.

Thanks for your prompt reply.

I understand that for a vector plot, DPlot needs a grid of positions (positions given by X and Y values) where the vectors are to be displayed. Then for each X,Y position, DPlot also needs a value for the vector magnitude and a value for the the vector direction (angle).

I have values for all of the positions (X and Y), but for some of the X and Y positions, I do not have data for vector magnitude and direction. For the positions where I have no magnitude and direction, I tried using zeros for magnitude and direction. But DPlot still displays the vector arrowhead, even for values of zero.

Ideally, I would like to simply show no vector at all at positions where I have no values for vector magnitude and vector direction.

A similar problem could happen for other types of plots, like surface or contour plots, where some of the Z values are missing for some of the X,Y positions.

Thanks again for you help with this.
Best regards,
Frank

For the positions where I have no magnitude and direction, I tried using zeros for magnitude and direction. But DPlot still displays the vector arrowhead, even for values of zero.

The magnitude can also be negative, so there's nothing magic about 0.

Ideally, I would like to simply show no vector at all at positions where I have no values for vector magnitude and vector direction.

Delete the corresponding X,Y point. There's no other way.

Thanks for explaining. So I can simply delete the X and Y values for positions where I have no values for magnitude and direction. That's what I'll do.

I did also find that if I delete just the magnitude and direction, and use a comma delimited csv format, no vectors are shown for positions where I have no magnitude and direction values.

Thanks for your help with this!
Frank

I did also find that if I delete just the magnitude and direction, and use a comma delimited csv format, no vectors are shown for positions where I have no magnitude and direction values.

That's not what I would have expected, unless I misunderstand what you did. Unless you also deleted the Y value I'd expect everything to get out of synch, with the magnitude and direction value for the (i+1)th point being used for the i'th X,Y point.