Extending the curtain plot (reference plane) when 3D plotting with meshz

Hi all,

I am using to meshz to display a 3D plot, but the curtain only extends to the extrema of the data points. In this particular case, the curtain falls inconveniently above the height 0.

Is it possible to drop the curtain to a specified height, namely 0? If so, how?

 -Thanks,
  Hussain

Answer 1

[the cyclist]

The values you want are stored in the "ZData" property of the plot. So, you need to grab those data, modify them, and set them again. The code below is something like what you need, although I am not 100% I understood whether you wanted to cut off below or above zero, so you might need to adjust things.

oldZData = get(get(gca,'Children'),'ZData')
newZData = min(0,oldZData);
set(get(gca,'Children'),'ZData',newZData)

EDIT IN RESPONSE TO COMMENT:

oldZData = get(get(gca,'Children'),'ZData');
newZData = oldZData;
newZData(min(oldZData(:))==oldZData) = 0;
set(get(gca,'Children'),'ZData',newZData)

[Hussain]

Cyclist,

Thanks for your response, but implementing the code directly flat-lines my 3D plot. All my current data is > 0; I'm hoping to pull the curtain down to = 0 rather than the minimum height of my data.

The edges of the 3D plot are ambiguous with a curtain falling > 0 which is why I wish to pull them down.

Thanks!

[the cyclist]

OK. I think I understand. I have added some different code to my answer, that I think does what you want. It identifies the points that are at the bottom of the current curtain, replaces those points with zeros, and redraws the new curtain.

[Hussain]

Thanks! Your suggestion mostly solves the problem; it certainly pulls the curtain down to zero as I had hoped. However, by setting the minimum data point (or any data point for that matter) to zero, the presented data also has a false 0.

I managed to solve the problem in sort of a one-time-use-be-very-careful way by examining the meshz routine. The original programmer conveniently marked where the position of the curtain is defined, zref, as the minimum of a the finite z matrix. I made a modified copy of the routine in which zref = 0, which does the trick very cleanly in this case.

Thanks for your help! Your answer motivated my investigation into the meshz routine.