MATLAB: Totally incorrect calculation of matlab

MATLABnot a bugquiver

I used quiver to plot a vector field. the code was :

 [x,y]=meshgrid(0:1:20);
 quiver(x,y,x^3-3*x*y,y^3-3*x^2*y)

However the results were completely different from expected, showing downward arrow at x=0, which should have been upward. Other arrows didn't match either.

Best Answer

Jaein, use instead

 [x,y] = meshgrid(0:1:20); 
 quiver(x,y,x.^3-3*x.*y,y.^3-3*x.^2.*y)   % note the dot-notation

Related Solutions

MATLAB: How to increase Quiver_tri arrow length

Quiver_tri arrow length

When I tried, the arrow length is adjusted with gird number.

[x,y] = meshgrid(0:0.5:2,0:0.5:2);
u = cos(x).*y;
v = sin(x).*y;
figure
quiver(x,y,u,v)

[x,y] = meshgrid(0:0.2:2,0:0.2:2);
u = cos(x).*y;
v = sin(x).*y;
figure
quiver(x,y,u,v)

MATLAB: Quiver Plot from matrices

What do you mean by not wanting to give quiver the values it needs? Not sure how you would create the plot without doing that. Here's how I would recreate your plot.

xComponent = zeros(5,5);
xComponent(3,3) = 1;
yComponent = zeros(5,5);
yComponent(3,3) = 2;
[Y,X]=meshgrid(1:size(xComponent,1),1:size(xComponent,2));
figure
plot(X,Y,'k.','MarkerSize',10)
hold on
quiver(X,Y,yComponent,-xComponent,2)

Best Answer

Related Solutions

MATLAB: How to increase Quiver_tri arrow length

MATLAB: Quiver Plot from matrices

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