matlab怎样读取grd格式的图像数据并绘图

% 读入grd数据，利用arcgridread
[Z,R] = arcgridread('MtWashington-ft.grd');
% 利用mapshow显示地图数据
mapshow(Z,R,'DisplayType','surface');
% 标记
xlabel('x (easting in meters)');
ylabel('y (northing in meters)')
colormap(demcmap(Z))
% View the terrain in 3-D
axis normal; view(3);
axis equal;
grid on
zlabel('elevation in feet')