二维等高线 k=2*((1-xx.^2).*(1-yy.^2)-sqrt(1-xx.^2).*sqrt(1-yy.^2)

二维等高线 k=2*((1-xx.^2).*(1-yy.^2)-sqrt(1-xx.^2).*sqrt(1-yy.^2).*xx.*yy)./(2-xx.^2-yy.^2)
将该函数在圆心为圆点半径为1的圆形区域内画二维等高线,我只能在正方形里画.以下是我用matlab编的程序,
function tjsfb222()
x=-1/sqrt(2):0.01:1/sqrt(2)
y=-1/sqrt(2):0.01:1/sqrt(2)
[xx yy]=meshgrid(x,y)
k=2*((1-xx.^2).*(1-yy.^2)-sqrt(1-xx.^2).*sqrt(1-yy.^2).*xx.*yy)./(2-xx.^2-yy.^2)
contour(xx,yy,k,100)
[c,h] = contour(k);clabel(c,h),colorbar
grid on