griddata调用方法 matlab griddata v4

griddata 调用方法：ZI = griddata(x,y,z,XI,YI)[XI,YI,ZI] = griddata(x,y,z,XI,YI)[...] = griddata(...,method)[...] = griddata(...,method,options)method 的值 为'linear' -- 则，以三角形为基础的线性内插'cubic' -- 则，以三角形为基础的三次方程内插'nearest' -- 则，用最邻近的点 内插'v4'-- -- 则，MATLAB 4 格点样条函数内插默认'linear' 线性内插三角形为基础，就是按Delaunay方法先找出内插点四周的3个点，构成三角形，内插点在三角形内。然后线性内插，或三次方程内插。'cubic' 和 'v4' 插值结果构成的曲面较光滑，'linear'和 'nearest' 插值结果构成的曲面不光滑不连续。

知道一系列点的坐标如下（1.486,3.059,0.1）;（2.121,4.041,0.1）;（2.570,3.959,0.1）;（3.439,4.396,0.1）;（4.505,3.012,0.1）;（3.402,1.604,0.1）;（2.570,2.065,0.1）;（2.150,1.970,0.1）;（1.794,3.059,0.2）;（2.121,3.615,0.2）;（2.570,3.473,0.2）;（3.421,4.160,0.2）;（4.271,3.036,0.2）;（3.411,1.876,0.2）;（2.561,2.562,0.2）;（2.179,2.420,0.2）;（2.757,3.024,0.3）;（3.439,3.970,0.3）;（4.084,3.036,0.3）;（3.402,2.077,0.3）;（2.879,3.036,0.4）;（3.421,3.793,0.4）;（3.953,3.036,0.4）;（3.402,2.219,0.4）;（3.000,3.047,0.5）;（3.430,3.639,0.5）;（3.822,3.012,0.5）;（3.411,2.385,0.5）;（3.103,3.012,0.6）;（3.430,3.462,0.6）;（3.710,3.036,0.6）;（3.402,2.562,0.6）;（3.224,3.047,0.7）;（3.411,3.260,0.7）;（3.542,3.024,0.7）;（3.393,2.763,0.7）怎样用MATLAB绘制成三维曲面呢？使用griddata插值A=[1.486,3.059,0.1;2.121,4.041,0.1;2.570,3.959,0.1;3.439,4.396,0.1;4.505,3.012,0.1;3.402,1.604,0.1;2.570,2.065,0.1;2.150,1.970,0.1;1.794,3.059,0.2;2.121,3.615,0.2;2.570,3.473,0.2;3.421,4.160,0.2;4.271,3.036,0.2;3.411,1.876,0.2;2.561,2.562,0.2;2.179,2.420,0.2;2.757,3.024,0.3;3.439,3.970,0.3;4.084,3.036,0.3;3.402,2.077,0.3;2.879,3.036,0.4;3.421,3.793,0.4;3.953,3.036,0.4;3.402,2.219,0.4;3.000,3.047,0.5;3.430,3.639,0.5;3.822,3.012,0.5;3.411,2.385,0.5;3.103,3.012,0.6;3.430,3.462,0.6;3.710,3.036,0.6;3.402,2.562,0.6;3.224,3.047,0.7;3.411,3.260,0.7;3.542,3.024,0.7;3.393,2.763,0.7];x=A(:,1);y=A(:,2);z=A(:,3);scatter(x,y,5,z)%散点图figure[X,Y,Z]=griddata(x,y,z,linspace(1.486,4.271)',linspace(1.604,4.276),'v4');%插值pcolor(X,Y,Z);shading interp%伪彩色图figure,contourf(X,Y,Z) %等高线图figure,surf(X,Y,Z)%三维曲面

x = rand(1,12);y = rand(1,12);z = rand(1,12); % now use some random z axis dataxi = linspace(min(x),max(x),30);        % x interpolation pointsyi = linspace(min(y),max(y),30);        % x interpolation points[Xi,Yi] = meshgrid(xi,yi);              % create grid of x and yZi = griddata(x,y,z,Xi,Yi);             % grid the data at Xi,Yi points% Zi = griddata(x,y,z,Xi,Yi, 'linear')          % same as above(default)% Zi = griddata(x,y,z,Xi,Yi, 'cubic')           % triangle based cubic interpolation% Zi = griddata(x,y,z,Xi,Yi, 'nearest') % triangle based nearest neighbor% Zi = griddata(x,y,z,Xi,Yi, 'invdist')         % inverse distance methodmesh(Xi,Yi,Zi)hold onplot3(x,y,z, 'ko')      % show original data as wellhold offtitle('Figure 18.10: Griddata Example') 

【问题描述】

有三列数字保存于excel表格中，现在想把这三列数字画成三维图。

【解决方法】

只有三类数字是不可能画出三维图的，需要插值转换一下，才能画出网格图或者更好的插值方法得到更光滑的曲面图。

【Matlab代码】

clc; clear all; close all;
A=xlsread('D:BackupMyDocumentsMATLABdata.xls');%读入数据
x=A(:,1);y=A(:,2);z=A(:,3);

t1=linspace(min(x),max(x));
t2=linspace(min(y),max(y));
[X,Y]=meshgrid(t1,t2);

Z=griddata(x,y,z,X,Y,'v4');
figure,surf(X,Y,Z),axis([19.37,19.92,209.3,229.7,220,260]);%三维曲面
xlabel('sigma/mm');grid on;
ylabel('Maximum Stress/MPa');grid on;
zlabel('h1/mm');grid on;
title('关系图');

【最终效果图】

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