how to show only a part of a surface fit that falls within a certain polygon

2 次查看（过去 30 天）
Dany
Dany 2015-2-12
评论： Dany 2015-2-15
Hi, i have created a surface fit using the next code:
*ft = 'thinplateinterp';
[fitresult, gof] = fit( [xData, yData], zData, ft );*
the next thing i want to do is to plot that surface, so i use:
*figure( 'Name', 'untitled fit 2' );
h = plot(fitresult);*
the problem is that it creats the surface over areas that i am not intrested in, so i have two parameters x and y that creats a closed polygon and i would like to show the part of the surface that falls within this polygon. how can i do it? is it even possible?
thank you for your help

请先登录，再回答此问题。

采纳的回答

Mike Garrity
Mike Garrity 2015-2-12
The simplest is to set zData to nan for the points you want to discard. Consider this example:
[x,y,z] = peaks;
px = [0 4 2];
py = [-1 -1 2];
inpts = inpolygon(x,y,px,py);
z(inpts) = nan;
surf(x,y,z)
  3 个评论
显示 1更早的评论
Mike Garrity
Mike Garrity 2015-2-12
When you said "show" I assumed you meant you wanted to modify the surface which gets created by the plot method. Also, to discard the data outside, just do z(~inputs). Like so:
[x,y,z] = peaks;
f = fit([x(:),y(:)],z(:),'poly23');
h = plot(f);
px = [-1 3 3 2 2 0 0 -1];
py = [-1 -1 0 0 1 1 0 0];
inpts = inpolygon(h.XData,h.YData,px,py);
h.ZData(~inpts) = nan;
Dany
Dany 2015-2-15
ok. thank you. but one problem though.
when i write
inpts = inpolygon(h.XData,h.YData,px,py);
i get this error:
Attempt to reference field of non-structure array.
it is like "h" does not have any properties.

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Surface and Mesh Plots 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by