

Hi, I did the 2D filled contour plot with both Octave and Matlab with same script file; but the filled contour plots are very different. I also checked the data file and they are the same.
The following plot is from Octave
This one is from Matlab
And here is my script file run in both Octave and Matlab. data = importdata('error_demo_2.txt') ; % read file x = data(:,1); y = data(:,2); z = data(:,3); % Grid %x0 = min(x) ; x1 = max(x) ; %y0 = min(y) ; y1 = max(y) ; %N = 10 ; %x2 = linspace(x0,x1,N) ; %y2 = linspace(y0,y1,N) ; %[X,Y] = meshgrid(x2,y2) ; [X,Y] = meshgrid(sort(x),sort(y)); Z = griddata(x,y,z,X,Y,'linear'); figure (1) contourf(X,Y,Z); colormap ('jet') colorbar figure (2) meshc(X,Y,Z) colormap ('jet') colorbar figure (3) contour(X,Y,Z); %meshc(X,Y,Z) colormap ('jet') colorbar xlabel ('Vds') ylabel ('Ids(mA/mm)') title ('S11 VAEerr')
Anyone can tell me what is the reason for the difference and how to solve it?
Thanks,
TM


Hi, I did the 2D filled contour plot with both Octave and Matlab with same script file; but the filled contour plots are very different. I also checked the data file and they are the same.
The following plot is from Octave
This one is from Matlab
And here is my script file run in both Octave and Matlab. data = importdata('error_demo_2.txt') ; % read file x = data(:,1); y = data(:,2); z = data(:,3); % Grid %x0 = min(x) ; x1 = max(x) ; %y0 = min(y) ; y1 = max(y) ; %N = 10 ; %x2 = linspace(x0,x1,N) ; %y2 = linspace(y0,y1,N) ; %[X,Y] = meshgrid(x2,y2) ; [X,Y] = meshgrid(sort(x),sort(y)); Z = griddata(x,y,z,X,Y,'linear'); figure (1) contourf(X,Y,Z); colormap ('jet') colorbar figure (2) meshc(X,Y,Z) colormap ('jet') colorbar figure (3) contour(X,Y,Z); %meshc(X,Y,Z) colormap ('jet') colorbar xlabel ('Vds') ylabel ('Ids(mA/mm)') title ('S11 VAEerr')
Anyone can tell me what is the reason for the difference and how to solve it?
Thanks,
TM
What version of Octave are you using? What OS? Any packages installed?



TsoMin Chou wrote
> Hi,
> I did the 2D filled contour plot with both Octave and Matlab with same
> script file; but the filled contour plots are very different. I also
> checked the data file and they are the same.
>
> The following plot is from Octave
> [image: image.png]
>
> This one is from Matlab
> [image: image.png]
>
> And here is my script file run in both Octave and Matlab.
> data = importdata('error_demo_2.txt') ; % read file
> x = data(:,1);
> y = data(:,2);
> z = data(:,3);
> % Grid
> %x0 = min(x) ; x1 = max(x) ;
> %y0 = min(y) ; y1 = max(y) ;
> %N = 10 ;
> %x2 = linspace(x0,x1,N) ;
> %y2 = linspace(y0,y1,N) ;
> %[X,Y] = meshgrid(x2,y2) ;
> [X,Y] = meshgrid(sort(x),sort(y));
> Z = griddata(x,y,z,X,Y,'linear');
> figure (1)
> contourf(X,Y,Z);
> colormap ('jet')
> colorbar
> figure (2)
> meshc(X,Y,Z)
> colormap ('jet')
> colorbar
> figure (3)
> contour(X,Y,Z);
> %meshc(X,Y,Z)
> colormap ('jet')
> colorbar
> xlabel ('Vds')
> ylabel ('Ids(mA/mm)')
> title ('S11 VAEerr')
>
> Anyone can tell me what is the reason for the difference and how to solve
> it?
>
> Thanks,
>
> TM
>
>
>
>
> image.png (41K)
> < http://octave.1599824.n4.nabble.com/attachment/4689419/0/image.png>> image.png (25K)
> < http://octave.1599824.n4.nabble.com/attachment/4689419/1/image.png>Hi,
You did not attache the input file so that it is impossible for us to
reproduce and eventually diagnose this origin of the issue.
Could attach 'error_demo_2.txt'?
Pantxo

Sent from: http://octave.1599824.n4.nabble.com/OctaveGeneralf1599825.html


Doug,
It's V4.4.0 for windows. Just standard no extra packages.
TsoMin
Keep the list informed
Hi, I did the 2D filled contour plot with both Octave and Matlab with same script file; but the filled contour plots are very different. I also checked the data file and they are the same.
The following plot is from Octave
This one is from Matlab
And here is my script file run in both Octave and Matlab. data = importdata('error_demo_2.txt') ; % read file x = data(:,1); y = data(:,2); z = data(:,3); % Grid %x0 = min(x) ; x1 = max(x) ; %y0 = min(y) ; y1 = max(y) ; %N = 10 ; %x2 = linspace(x0,x1,N) ; %y2 = linspace(y0,y1,N) ; %[X,Y] = meshgrid(x2,y2) ; [X,Y] = meshgrid(sort(x),sort(y)); Z = griddata(x,y,z,X,Y,'linear'); figure (1) contourf(X,Y,Z); colormap ('jet') colorbar figure (2) meshc(X,Y,Z) colormap ('jet') colorbar figure (3) contour(X,Y,Z); %meshc(X,Y,Z) colormap ('jet') colorbar xlabel ('Vds') ylabel ('Ids(mA/mm)') title ('S11 VAEerr')
Anyone can tell me what is the reason for the difference and how to solve it?
Thanks,
TM
What version of Octave are you using? What OS? Any packages installed?



Le 17/09/2018 à 19:28, TsoMin Chou a
écrit :
Forwarding your email and the data file.
The Z output contains NaN in regions where no (x,y) pair was
provided and Octave doesn't seem to handle those well.
A workaround is to replace NaN values by some value lower than
the min value and and fix the countour levels by hand. Something
like
data = importdata('error_demo_2.txt') ; % read
file
x = data(:,1);
y = data(:,2);
z = data(:,3);
[X,Y] = meshgrid(sort(x),sort(y));
Z = griddata(x,y,z,X,Y,'linear');
figure (1)
minz = min (Z(:));
maxz = max (Z(:));
Z(isnan (Z)) = minz  (maxz  minz) /2;
[~, h] = contourf(X,Y,Z, linspace (minz, maxz,
10));
Pantxo

