quiver(X,Y,DX,DY)quiver(DX,DY)quiver(x,y,dx,dy,s)quiver(dx,dy,s)quiver(....'linetype')
quiver(X,Y,DX,DY) draws arrows at every pair of elements in matrices X and Y. The pairs of elements in matrices DX and DY determine the direction and relative magnitude of the arrows. If X and Y are vectors, they must have length(x) = n and length(y) = m where [m,n] = size(DX) = size(DY). In this case, the arrows represent (x(j),y(i),DX(i,j), DY(i,j)). Note that vector X corresponds to the columns of DX and DY and Y corresponds to the rows.
quiver(DX,DY) uses x = 1:n and y = 1:m. In this case DX and DY are defined over a geometrically rectangular grid.
quiver(x,y,dx,dy,s) and quiver(dx,dy,s) apply scalar s as a scale factor to the lengths of the arrow. For example, s = 2 doubles their relative length and s = 0.5 halves them.
A final trailing string argument linetype specifies line type and color using any legal line specification as described under the plot command.
[x,y] = meshgrid(-2:.2:2);z = x.*exp(-x.^2-y.^2);[dx,dy] = gradient(z,.2,.2);contour(x,y,z)hold onquiver(x,y,dx,dy)hold off
contour,plot
(c) Copyright 1994 by The MathWorks, Inc.