フィルターのクリア

Contour plot of cubic interpolation with set number of contour levels

45 ビュー (過去 30 日間)
Joseph Cunningham
Joseph Cunningham 2024 年 9 月 5 日 19:00
編集済み: dpb 2024 年 9 月 6 日 18:18
I have 2 sets of raw experimental data arranged in a grid of X- and Y- points with Z-values at each point representing intensity. Xvec, Yvec, and Zvec are vectors of the same length (24) where corresponding positions give the X- and Y- positions and Z values. I have used a cubic interpolation to fit a surface to this data, and have been able to plot it with a contour plot function. My code is as below, with an example Xvec, Yvec, and Zvec provided.
Xvec= [-1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750]';
Yvec=[1.6250 1.6250 1.6250 0.5000 0.5000 0.5000 -0.6250 -0.6250 -0.6250 -1.8750 -1.8750 -1.8750 -1.8750 -1.8750 -1.8750 -0.6250 -0.6250 -0.6250 0.5000 0.5000 0.5000 1.6250 1.6250 1.6250]';
Zvec= [0.5516 0.7743 1.0936 1.1194 2.1194 2.6033 1.0840 2.1033 2.7903 0.4421 1.0936 0.7645 0.7420 0.4292 0.4292 2.6228 1.7775 0.9130 2.5453 1.7389 0.8743 1.0743 0.8358 0.6712]';
--Minimal coding example:
Zfit1=fit([Xvec Yvec],Zvec,'cubicinterp');
figure (1)
plot(Zfit1,[Xvec Yvec],Zvec,'Style','Contour')
c=colorbar;
cc=get(c,'Limits');
set(c,'Ticks',linspace(cc(1),cc(2),10))
set(gcf,'color','w');
--End example
Yields the following figure:
I would like to have both the contour of the fit and the X-Y data points on the chart, as above, but I would like to have 12 instead of 6 color/contour levels.
I would appreciate any assistance that can be provided by the community.
Thank you in advance.
JC

採用された回答

John D'Errico
John D'Errico 2024 年 9 月 5 日 19:19
編集済み: John D'Errico 2024 年 9 月 5 日 19:25
Simple enough. You should have looked at the handle returned by plot. Though I guess it helps if you know what to look for. ;-)
Xvec= [-1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750]';
Yvec=[1.6250 1.6250 1.6250 0.5000 0.5000 0.5000 -0.6250 -0.6250 -0.6250 -1.8750 -1.8750 -1.8750 -1.8750 -1.8750 -1.8750 -0.6250 -0.6250 -0.6250 0.5000 0.5000 0.5000 1.6250 1.6250 1.6250]';
Zvec= [0.5516 0.7743 1.0936 1.1194 2.1194 2.6033 1.0840 2.1033 2.7903 0.4421 1.0936 0.7645 0.7420 0.4292 0.4292 2.6228 1.7775 0.9130 2.5453 1.7389 0.8743 1.0743 0.8358 0.6712]';
Zfit1=fit([Xvec Yvec],Zvec,'cubicinterp');
figure (1)
H = plot(Zfit1,[Xvec Yvec],Zvec,'Style','Contour')
H =
2x1 graphics array: Contour (curvefit.gui.FunctionContour) Line
Note that H is an array of two handles. The first one is what we need.
c=colorbar;
cc=get(c,'Limits');
set(c,'Ticks',linspace(cc(1),cc(2),10))
set(gcf,'color','w');
If we take a look at what is stuffed in there,
get(H(1))
Annotation: [1x1 matlab.graphics.eventdata.Annotation] BeingDeleted: off BusyAction: 'queue' ButtonDownFcn: '' Children: [0x0 GraphicsPlaceholder] Clipping: on ContextMenu: [0x0 GraphicsPlaceholder] ContourMatrix: [2x560 double] CreateFcn: '' DataTipTemplate: [1x1 matlab.graphics.datatip.DataTipTemplate] DeleteFcn: '' DisplayName: '' EdgeAlpha: 1 EdgeColor: [0.0706 0.0706 0.0706] FaceAlpha: 1 FaceColor: 'flat' HandleVisibility: 'on' HitTest: off Interruptible: on LabelColor: [0.1300 0.1300 0.1300] LabelFormat: @string LabelSpacing: 144 LevelList: [0.3945 0.5000 1 1.5000 2 2.5000] LevelListMode: 'auto' LevelStep: 0.5000 LevelStepMode: 'auto' LineStyle: '-' LineWidth: 0.5000 Parent: [1x1 Axes] PickableParts: 'none' Selected: off SelectionHighlight: on ShowText: off Tag: 'curvefit.gui.FunctionContour' TextList: [0.5000 1 1.5000 2 2.5000] TextListMode: 'auto' TextStep: 0.5000 TextStepMode: 'auto' Type: 'contour' UserData: [] Visible: on XData: [51x49 double] XDataMode: 'manual' XDataSource: '' YData: [51x49 double] YDataMode: 'manual' YDataSource: '' ZData: [51x49 double] ZDataSource: '' ZLocation: 0
Look at what you can set there. The set of levels originally chosen by the plot code were (in LevelList):
[0.3945 0.5000 1 1.5000 2 2.5000]
It looks like the min was probably at 0.3945. So I'll choose a different set now.
H(1).LevelList = .4:.1:2.5;
  3 件のコメント
Joseph Cunningham
Joseph Cunningham 2024 年 9 月 5 日 20:59
Thank you both for your suggestions and assistance. I'll play around with this a bit tomorrow, but it looks to be performing as I hoped! :-)
John D'Errico
John D'Errico 2024 年 9 月 5 日 22:33
As I said, these things are always simpler when you know to look there. ;-) The good thing about Answers is we all learn something new everyday. I know I do.

サインインしてコメントする。

その他の回答 (1 件)

dpb
dpb 2024 年 9 月 5 日 19:42
編集済み: dpb 2024 年 9 月 6 日 18:18
Xvec= [-1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 -1.8750 -1.1250 -0.3750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750 0.3750 1.1250 1.8750]';
Yvec=[1.6250 1.6250 1.6250 0.5000 0.5000 0.5000 -0.6250 -0.6250 -0.6250 -1.8750 -1.8750 -1.8750 -1.8750 -1.8750 -1.8750 -0.6250 -0.6250 -0.6250 0.5000 0.5000 0.5000 1.6250 1.6250 1.6250]';
Zvec= [0.5516 0.7743 1.0936 1.1194 2.1194 2.6033 1.0840 2.1033 2.7903 0.4421 1.0936 0.7645 0.7420 0.4292 0.4292 2.6228 1.7775 0.9130 2.5453 1.7389 0.8743 1.0743 0.8358 0.6712]';
Zfit1=fit([Xvec Yvec],Zvec,'cubicinterp');
[X,Y]=meshgrid(linspace(min(Xvec),max(Xvec)),linspace(min(Yvec),max(Yvec)));
Zpred=Zfit1(X,Y);
%whos X* Y* Z*
hC=contourf(X,Y,Zpred,12);
c=colorbar;
%cc=get(c,'Limits');
%set(c,'Ticks',linspace(cc(1),cc(2),10))
set(gcf,'color','w');
That seems strange that the builtin fit object contour option doesn't have the number of levels as a property, but doesn't seem to have.
It appears you are short of data to create a smooth plot and that there may be a case of the cubic rolling over, maybe???
figure
hC3=contour3(X,Y,Zpred,12);
figure
% repeat John's specific levels
LevelList = 0.4:0.1:2.5;
contourf(X,Y,Zpred,LevelList);
colorbar
ADDENDUM: Evaluating the fit at a finer grid smooths out the plot...
One more slight perturbation -- add a finer delta at the peak...
[min(Zpred,[],'all') max(Zpred,[],'all')]
ans = 1x2
0.3937 2.9458
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
figure
hC3=contour3(X,Y,Zpred,12);
figure
% augment John's specific levels to see shape of peak more fully
LevelList = [0.3:0.1:2.5 2.55:0.05:3.0];
contourf(X,Y,Zpred,LevelList,'ShowText',1);
colorbar

カテゴリ

Help Center および File ExchangeSurface and Mesh Plots についてさらに検索

製品


リリース

R2024a

Community Treasure Hunt

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

Start Hunting!

Translated by