# how to plot Contour Plot?

조회 수: 4(최근 30일)
댓글: Star Strider 15 Dec 2019
I have 3 variables data in xls file. I want to plot contour plot of one variable against other 2 variables on x and y axis. How do I do this?

댓글을 달려면 로그인하십시오.

### 채택된 답변

Star Strider 15 Dec 2019
I assume your variables are vectors. If they are gridded, it is only necessary to use the reshape function to form them into matrices.
If they are not gridded, something like this will work:
x = rand(20, 1);
y = rand(20, 1);
z = rand(20, 1);
xv = linspace(min(x), max(x), 50);
yv = linspace(min(y), max(y), 50);
[X,Y] = ndgrid(xv, yv);
Z = griddata(x, y, z, X, Y);
figure
contourf(X, Y, Z)
Experiment to get the result you want.
##### 댓글 수: 4표시숨기기 이전 댓글 수: 3
Star Strider 15 Dec 2019
If you know the values you want for the contours, the easiest way is to specify them in a vector as the fourth argument to contourf:
x = rand(20, 1);
y = rand(20, 1);
z = rand(20, 1)*100;
xv = linspace(min(x), max(x), 50);
yv = linspace(min(y), max(y), 50);
[X,Y] = ndgrid(xv, yv);
Z = griddata(x, y, z, X, Y);
colorcol = linspace(0.1, 0.9, 10); % Define Number Of Intensities (Here 10)
cmap = zeros(numel(colorcol), 3); % Define ‘colormap’ Here
cmap(:,2) = colorcol(:); % Choose Green ([R G B])
figure
contourf(X, Y, Z, [20 40 60 80], 'ShowText','on')
colormap(cmap)
Here the plot shows only the contours at [20 40 60 80]. Specify whatever values you want.

댓글을 달려면 로그인하십시오.

### Community Treasure Hunt

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

Start Hunting!

Translated by