Matplotlib 颜色图映射与稳定值

Question

thanks for help.

Here is the question:

I have some values of earthquake Intensity(1, 2, 3, 4, 5, 5.5, 6, 6.5, 7 total 9 levels), And I also have 9 colors for colormap.

    color_map = [
        '#f3f3f3',
        '#1aff1a',
        '#ffff00',
        '#ff8900',
        '#ff5500',
        '#b64100',
        '#993300',
        '#aa3c00',
        '#800080'
]
cm = matplotlib.colors.ListedColormap(color_map)

draw_area.plot("Intensity", ax=axes, cmap=cm, legend=True) #it suppose to be mapped by "Intensity" values

and two cases happened

Situation1: If I got many "different" values of "Intensity" such as 1,2,3,4,5,6,6.5,7 than my map came out with many colors like this.

Situation2: If I got many "Same" values of "Intensity" such as 4,4,4,4,4 or 5,5,5,5,5 than my map will not map the colormap, it came out with same color.(all areas mapped by the first color #f3f3f3)

I want to map the color "one value to one color", how to solve this?(if i got 2,2,2,2, these areas suppose to be mapped by #1aff1a)

Thanks for help!

Answer 1

I have found the method to this situation, I need to use absolute value to map the colors.

So I fix the code, and it works!

here is the code:

cmap, norm = matplotlib.colors.from_levels_and_colors(cLevel, color_map, extend="max")

Using from_levels_and_colors to get absolute mapping.