extracting all other variables on a contour level

I have a x-y meshgrid with different variables in it. I plot a contour level of f1 using [c,h]=contour(x,y,f1,clev):

Now I need to save other variables like f2,f3,... only on the shown contour level of f1 (blue line) in a matrix.

[Adam Danz]

The easiest way is to use one of the functions on the file exchange that receive the contour() outputs and return the contour coordinates for each level.

• Table output: https://www.mathworks.com/matlabcentral/fileexchange/74010-getcontourlinecoordinates
• Structure output: https://www.mathworks.com/matlabcentral/fileexchange/38863-extract-contour-data-from-contour-matrix-c
• Cell array output: https://www.mathworks.com/matlabcentral/fileexchange/43162-c2xyz-contour-matrix-to-coordinates

[Roozbeh Saghatchi]

Thank you Adam,

x and y position have already calculated in [c,h]=contour(x,y,f1,clev). Now how can I relate it to another function f2(x,y) at those specific x and y values?

[Adam Danz]

The functions I mentioned do not calculate the x,y values. They only reorganize the c or h outputs of contour() by level. For example, using the first one in my list,

% Reorganize the contour outputs into a table. 
[cm, h] = contour(x,y,f1,clev);
contourTable = getContourLineCoordinates(cm);

% Look at first few rows of the table (fake data)
% 4×4 table
%       Level      Group        X         Y  
%     ________    _______    _______    _______
%     -5.8504        1        0.44266     -1.75
%     -5.8504        1        0.375       -1.8038
%     -5.8504        1        0.25        -1.8526
%     -5.8504        1        0.125       -1.8498

% Get the index for all rows at level #7 (you could also index by group number)
levelIdx = contourTable.Level == h.LevelList(7);
% or
% levelIdx = contourTable.Group == 7;

% Use the x and y values 
x(levelIdx)
y(levelIdx)