countourf在Matlab中不顯示彩色區域

Question

我應該在我的代碼中更改countorf顯示哪些區域具有更多色差？

clear all; 
close all; 
phi=90; 
[xx,yy] = meshgrid(-20:0.1:20,-20:0.1:20); 
Idontwantthis = (xx.^2+yy.^2)<0.1; 
u = (xx./(xx.^2+yy.^2).^(3/2)); 
v = (yy./(xx.^2+yy.^2).^(3/2)); 
data= sqrt(u.^2+v.^2); 
data(Idontwantthis)=NaN; 
u(Idontwantthis)=NaN; 
v(Idontwantthis)=NaN; 
contourf(xx,yy,data,20); 

Answer 1

首先，你不需要meshgrid超過[-20 20]。嘗試將範圍縮小至[-2 2]。運行contourf後，改變顏色表：

clear all; 
close all; 
phi=90; 

[xx,yy] = meshgrid(-2:0.01:2,-2:0.01:2); 

Idontwantthis = (xx.^2+yy.^2)<0.1; 
u = (xx./(xx.^2+yy.^2).^(3/2)); 
v = (yy./(xx.^2+yy.^2).^(3/2)); 
data= sqrt(u.^2+v.^2); 
data(Idontwantthis)=NaN; 
u(Idontwantthis)=NaN; 
v(Idontwantthis)=NaN; 

contourf(xx,yy,data,20); 
colormap hsv; 

這是你的結果將是什麼樣子：

希望幫助！