首先，您需要一个将波长作为输入并返回RGB颜色的函数。这样的功能可以在这里找到。可以使它适应返回一个Alpha值，该Alpha值在可见颜色范围之外小于1。
此功能可用于创建颜色图。使用体面的归一化可以将波长范围映射到0到1之间的范围，以便可以在imshow图中使用此色图。
import numpy as npimport matplotlib.pyplot as pltimport matplotlib.colorsdef wavelength_to_rgb(wavelength, gamma=0.8): ''' taken from http://www.noah.org/wiki/Wavelength_to_RGB_in_Python This converts a given wavelength of light to an approximate RGB color value. The wavelength must be given in nanometers in the range from 380 nm through 750 nm (789 THz through 400 THz). based on pre by Dan Bruton http://www.physics.sfasu.edu/astro/color/spectra.html Additionally alpha value set to 0.5 outside range ''' wavelength = float(wavelength) if wavelength >= 380 and wavelength <= 750: A = 1. else: A=0.5 if wavelength < 380: wavelength = 380. if wavelength >750: wavelength = 750. if wavelength >= 380 and wavelength <= 440: attenuation = 0.3 + 0.7 * (wavelength - 380) / (440 - 380) R = ((-(wavelength - 440) / (440 - 380)) * attenuation) ** gamma G = 0.0 B = (1.0 * attenuation) ** gamma elif wavelength >= 440 and wavelength <= 490: R = 0.0 G = ((wavelength - 440) / (490 - 440)) ** gamma B = 1.0 elif wavelength >= 490 and wavelength <= 510: R = 0.0 G = 1.0 B = (-(wavelength - 510) / (510 - 490)) ** gamma elif wavelength >= 510 and wavelength <= 580: R = ((wavelength - 510) / (580 - 510)) ** gamma G = 1.0 B = 0.0 elif wavelength >= 580 and wavelength <= 645: R = 1.0 G = (-(wavelength - 645) / (645 - 580)) ** gamma B = 0.0 elif wavelength >= 645 and wavelength <= 750: attenuation = 0.3 + 0.7 * (750 - wavelength) / (750 - 645) R = (1.0 * attenuation) ** gamma G = 0.0 B = 0.0 else: R = 0.0 G = 0.0 B = 0.0 return (R,G,B,A)clim=(350,780)norm = plt.Normalize(*clim)wl = np.arange(clim[0],clim[1]+1,2)colorlist = list(zip(norm(wl),[wavelength_to_rgb(w) for w in wl]))spectralmap = matplotlib.colors.LinearSegmentedColormap.from_list("spectrum", colorlist)fig, axs = plt.subplots(1, 1, figsize=(8,4), tight_layout=True)wavelengths = np.linspace(200, 1000, 1000)spectrum = (5 + np.sin(wavelengths*0.1)**2) * np.exp(-0.00002*(wavelengths-600)**2)plt.plot(wavelengths, spectrum, color='darkred')y = np.linspace(0, 6, 100)X,Y = np.meshgrid(wavelengths, y)extent=(np.min(wavelengths), np.max(wavelengths), np.min(y), np.max(y))plt.imshow(X, clim=clim, extent=extent, cmap=spectralmap, aspect='auto')plt.xlabel('Wavelength (nm)')plt.ylabel('Intensity')plt.fill_between(wavelengths, spectrum, 8, color='w')plt.savefig('WavelengthColors.png', dpi=200)plt.show()
