Matlab绘图的疑问

zxb1219

clear
A=[0.5,0.01,99.8826;
   0.5,0.1,99.9458;
   0.5,0.5,98.4111;
   0.5,1,96.3573;
   0.5,0.03,99.9142;
   0.5,0.05,99.9323;
   0.5,0.07,99.9323;
   0.5,0.3,99.9639;
   0.5,0.7,97.6889;
   1,0.01,17.1843;
   1,0.1,16.2409;
   1,0.5,13.1263;
   1,1,10.743;
   1,0.03,16.9721;
   1,0.05,16.7419;
   1,0.07,16.5794;
   1,0.3,14.5482;
   1,0.7,0;
   2.5,0.01,77.7015;
   2.5,0.1,76.2616;
   2.5,0.5,61.6322;
   2.5,1,44.7865;
   2.5,0.03,77.4307;
   2.5,0.05,77.1509;
   2.5,0.07,76.8981;
   2.5,0.3,71.003;
   2.5,0.7,55.1548;
   5,0.01,39.5459;
   5,0.1,37.9209;
   5,0.5,32.4772;
   5,1,25.2866;
   5,0.03,39.1577;
   5,0.05,38.8372;
   5,0.07,38.4671;
   5,0.3,34.8921;
   5,0.7,29.7328];
x=A(:,1);y=A(:,2);z=A(:,3);
怎样画出二维图像，使z值在0~30范围显示为浅绿色，在30~60范围显示为绿色，在60~90范围显示为深绿色，在>90范围显示为更深的绿色？

qibbxxt

用索引图