Need to draw a plane

Hello I have a 3d plot like this http://s10.postimage.org/k551sbnah/fig.jpg

in this fig I need to draw plane at z axis at 3.9*10^-3,,,from this plane i can specify which points lies above 0.0039 and below of it

any idea////

Answer 1

[Walter Roberson]

XL = get(gca, 'XLim');
YL = get(gca, 'YLim');
zpos = 0.0039
patch([XL([1 2 2 1 1]), YL([1 1 2 2 1]), zpos * ones(1,5));

[joy]

thanx walter

i used ur comment using just a parenthesis removed as it gave error as

    XL = get(gca, 'XLim');
YL = get(gca, 'YLim');
zpos = 0.0039
patch(XL([1 2 2 1 1]), YL([1 1 2 2 1]), zpos * ones(1,5));

but i get a fig like this..but in need plane at middle at point 0.0039 along prob of occurrence http://s8.postimage.org/6x3i95h45/untitled.jpg

[Walter Roberson]

Ah. Stupid thing assumes that a third argument is color rather than z! You need to add a color

patch(XL([1 2 2 1 1]), YL([1 1 2 2 1]), zpos * ones(1,5), [0 .2 .7]);

though probably you would want a lighter color. You might also want to use transparency, which is AlphaData

[joy]

thanx walter

I did not get ur views about what the changes I have to do if I need a transparent plane...

regards

[Walter Roberson]

transparency = 0.2;    %mostly clear
patch(XL([1 2 2 1 1]), YL([1 1 2 2 1]), zpos * ones(1,5), [0 .2 .7], 'AlphaData', transparency);

[joy]

using this command,I am getting following errors..how to rectify???

??? Error using ==> patch Bad property value found. Object Name : patch Property Name : 'AlphaDataMapping'

[Walter Roberson]

Sorry, should be 'FaceAlpha' instead of 'AlphaData'