#encoding=utf8import matplotlibfrom matplotlib import rcfrom matplotlib import pyplot as pltimport numpy as nprc('lines', linewidth=0.5)rc('font', family='sans-serif', size=10)rc('axes', labelsize=10)rc('xtick', labelsize=9)rc('ytick', labelsize=9)golden_mean = (np.sqrt(5)-1.0)/2.0inches_per_cm = 1.0/2.54fig_width = 8 * inches_per_cmfig_height = golden_mean * fig_widthfig = plt.figure(figsize = [fig_width, fig_height])from colorpy import ciexyz, colormodelsFs = 2.16e-5 * np.pi;   # Geometrical factor of sun as viewed from Earthh = 6.63e-34;           # Boltzmann const. [Js]c = 3.e8;               # speed of light [m/s]q = 1.602e-19;          # electron charge [C]def blackbody(wvlgth, temp):    # per nanometer 1e-9:    fac = (2 * Fs * h * c**2) / ((wvlgth * 1.e-9)**5)    return fac / (np.exp(1240./(wvlgth*8.62e-5*temp)) - 1) * 1.e-9def draw_vis_spec(ax, ymax):    spectrum = ciexyz.empty_spectrum()[:,0]    (num_wl,) = spectrum.shape    rgb_colors = np.empty((num_wl, 3))    for i in xrange (0, num_wl):        xyz = ciexyz.xyz_from_wavelength(spectrum[i])        rgb = colormodels.rgb_from_xyz(xyz)        rgb_colors [i] = rgb    rgb_colors /= np.max(rgb_colors) # scale to make brightest rgb value = 1.0        num_points = len(spectrum)    for i in xrange (0, num_points-1):        x0 = spectrum[i]        x1 = spectrum[i+1]        y0 = 0.0        y1 = ymax        poly_x = [x0, x1, x1, x0]        poly_y = [y0, y0, y1, y1]        color_string = colormodels.irgb_string_from_rgb(rgb_colors [i])        ax.fill(poly_x, poly_y, color_string, edgecolor=color_string)ax = fig.add_subplot(111)frame = ax.get_frame()frame.set_facecolor('black')xmax = 2000ymax = 2.5# Visible spectrum:draw_vis_spec(ax, ymax)# Blackbody:temp = 5777x = np.arange(100, 2000)y = blackbody(x, temp)y[-1] = 0.ax.fill(x, y, '0.5', alpha = 0.7, linewidth = 0.9, edgecolor='yellow', label = 'Black body\n%d K' % temp)# AM0 spectrum:d = np.loadtxt('smarts295.ext.txt', skiprows = 1)x = d[:,0]y = d[:,1]y[0] = 0.y[-1] = 0.ax.plot(x, y, color='white', linewidth=0.5, label = 'AM0')ax.set_xlim(0, xmax)ax.set_xticks(np.arange(0, 1999, 300))ax.set_ylim(0, ymax)# Tweak, tweak and annotate:texty = 2.25ax.annotate('UV', xy = (50,texty), xytext = (230,texty), xycoords = 'data',         horizontalalignment='left', verticalalignment='center', color='#33bb33',        arrowprops = dict(arrowstyle='->', color='#33bb33'))#ax.annotate('Synlig', xy=(400,texty), xycoords='data', #        horizontalalignment='left', verticalalignment='center', color='white')ax.annotate(u'Infrared', xytext = (720,texty), xy = (1900,texty), xycoords = 'data',         horizontalalignment='left', verticalalignment='center', color='#33bb33',         arrowprops = dict(arrowstyle='->',color='#33bb33'))leg = ax.legend(loc='upper right', frameon=False, bbox_to_anchor = (1.0, 0.90) )txts = leg.get_texts()for txt in txts:    txt.set_color('white')    txt.set_fontsize(9)ax.tick_params(color='white', labelcolor='black')for spine in ax.spines.values():    spine.set_edgecolor('white')    spine.set_linewidth(1.4)fig.subplots_adjust(left=0.16, bottom = 0.19, right=0.98, top=0.96)ax.set_xlabel(u'Wavelength [nm]')ax.set_ylabel(u'Irradiance [W/m$^2$/nm]')fig.savefig('Solar AM0 spectrum with visible spectrum background (en).png',dpi=600)