Problem with contourf for scattered data
11 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Cyril Basalaev
le 15 Mai 2019
Modifié(e) : Cyril Basalaev
le 20 Mai 2019
Hello!
I have a table with 3 columns (x,y,value) for scattered data from the image like this.
But when I take griddata and then contouf, I get such a plot with strange netted area (in the bottom). Blue points are my sctttered data
Area in the bottom large (small bubbles):
So the question is what am i doing wrong? Why do I get these netted areas instead of great filled areas? Why i get it i these places and others are ok&
Listing of my code, table in attachments
[xq,yq] = meshgrid(0:1:3550, 0:1:2550); % interpolation points grid
vq = griddata(x,y,values,xq,yq,'natural');
Z = squeeze(vq);
grid on
[hq,hqlbl] = contourf(xq,yq,Z);
clabel(hq,hqlbl)
colorbar ('Direction','reverse')
caxis([-60 20])
2 commentaires
Cris LaPierre
le 15 Mai 2019
Modifié(e) : Cris LaPierre
le 15 Mai 2019
Which column contains value? Your spreadsheet has 10 columns in it. X and Y are obvious, but not sure what you want to use for elevation.
Perhaps you could describe what it is you are trying to do? If you could explain what you want your final result to be, we can better help you decide what it is you should do.
Réponse acceptée
Cris LaPierre
le 15 Mai 2019
Modifié(e) : Cris LaPierre
le 15 Mai 2019
I didn't look into what is causing it, but inspecting Z has me thinking it might be roundoff error. Your Z values in this region are varying between 1 and 1.0000. Since your contour line is for Z==1, I suspect it is trying to create a contour line around each 1.0000 "island".
I was able to clear it up for the 1/23/2017 data by adding round to the following code:
Z = squeeze(round(vq,4));
1 commentaire
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Data Distribution Plots dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!