Get values of the particular line from surf plot

Question

Ramesh Bala 2021-9-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1446009-get-values-of-the-particular-line-from-surf-plot

评论： Ramesh Bala 2021-9-3

采纳的回答： Konrad

jj.mat

在 MATLAB Online 中打开

I'm intersted to get all the values of the line 2- curve - marked in figure

load('jj.mat');
A1  = jj;
figure
A1(A1>0.05) = NaN;
surf(A1);shading interp;view(2);
figure
contour(A1); shading interp; view(2)
figure
v = [0.045 0.055];
contour3(A1,v); shading interp; view(2)

How Shall I get only this lower curve in a separate figure and then get all the Y values ?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Konrad 2021-9-3

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1446009-get-values-of-the-particular-line-from-surf-plot#answer_780144

在 MATLAB Online 中打开

Hi Ramesh,

the contour3() function returns the contour matrix (see help) containing x- and y-coordinates of the contour. You can use these to extract the desired part of the contour:

figure
v = [0.045 0.055];
contMat = contour3(A1,v); shading interp; view(2)
idx = contMat(1,:)>60 & contMat(2,:) < 850;
contSubset = contMat(:,idx);

Now contSubset contains x coordinates of the marked part in the first row and y coordinates in the second row.

Best, Konrad

3 个评论
显示 1更早的评论隐藏 1更早的评论

Konrad 2021-9-3

编辑：Konrad 2021-9-3

在 MATLAB Online 中打开

Try

figure;
plot(contSubset(1,:),contSubset(2,:),'.'); % 1st row of contSubset is used as x-coordinates and 2nd row as y-ccordinates
set(gca,'Xlim',[1 234],'YLim',[1 2643])

this should look like the region marked in your figure.

Ramesh Bala 2021-9-3