根据当前的色彩图选择一种颜色(Pick a color according to current colormap)

根据当前的色彩图选择一种颜色(Pick a color according to current colormap)

我的图包含许多半透明的等值面以显示密度。 我选择70：140范围的颜色：

vs=griddata(x,y,z,v,xs,ys,zs,'linear'); for i=70:5:140 p(i)=patch(isosurface(xs,ys,zs,vs,i)); isonormals(xs,ys,zs,vs,p(i)); rd=(i-70)/70; set(p(i),'facealpha',0.5); set(p(i),'FaceColor',[rd 0 1-rd],'EdgeColor','none'); % set colors end; alpha(0.3);

因此，这里的颜色从蓝色（密度= 70）到红色（密度= 140）不等。 如何从当前的colormap获取给定范围的颜色？

My graph contains a number of semi-transparent isosurfaces to visualize density. I choose the color for a range 70:140:

vs=griddata(x,y,z,v,xs,ys,zs,'linear'); for i=70:5:140 p(i)=patch(isosurface(xs,ys,zs,vs,i)); isonormals(xs,ys,zs,vs,p(i)); rd=(i-70)/70; set(p(i),'facealpha',0.5); set(p(i),'FaceColor',[rd 0 1-rd],'EdgeColor','none'); % set colors end; alpha(0.3);

So, here the colors vary from blue (density=70) to red (density=140). How to get a color for a given range from the current colormap?

最满意答案

文档说明了如何使用fix函数将值映射到colormap。

下面是您给出的范围的示例，其中可以使用cmap(index(i),:)访问颜色，范围为rng ：

rng=70:5:140; cmap = colormap; m = size(cmap,1); index = fix((rng-min(rng))/range(rng)*m)+1; index(index<1) = 1; index(index>m) = m; % Plot example hold on; arrayfun(@(i) plot(rng(i),rng(i),'.', ... 'markersize',30,'color',cmap(index(i),:)),1:length(rng)); colorbar; hold off;

此示例输出以下图：

The documentation explains here how the values are mapped to the colormap using the fix function.

Here is an example for the range you gave, where the color can be accessed using cmap(index(i),:) for an i in the range rng:

rng=70:5:140; cmap = colormap; m = size(cmap,1); index = fix((rng-min(rng))/range(rng)*m)+1; index(index<1) = 1; index(index>m) = m; % Plot example hold on; arrayfun(@(i) plot(rng(i),rng(i),'.', ... 'markersize',30,'color',cmap(index(i),:)),1:length(rng)); colorbar; hold off;

This example outputs the following plot: