colorbar_example4.py

def get_continuous_cmap(hex_list, float_list=None):
    ''' creates and returns a color map that can be used in heat map figures.
        If float_list is not provided, colour map graduates linearly between each color in hex_list.
        If float_list is provided, each color in hex_list is mapped to the respective location in float_list. 
        
        Parameters
        ----------
        hex_list: list of hex code strings
        float_list: list of floats between 0 and 1, same length as hex_list. Must start with 0 and end with 1.
        
        Returns
        ----------
        colour map'''
    rgb_list = [rgb_to_dec(hex_to_rgb(i)) for i in hex_list]
    if float_list:
        pass
    else:
        float_list = list(np.linspace(0,1,len(rgb_list)))
        
    cdict = dict()
    for num, col in enumerate(['red', 'green', 'blue']):
        col_list = [[float_list[i], rgb_list[i][num], rgb_list[i][num]] for i in range(len(float_list))]
        cdict[col] = col_list
    cmp = mcolors.LinearSegmentedColormap('my_cmp', segmentdata=cdict, N=256)
    return cmp

x, y = np.mgrid[-5:5:0.05, -5:5:0.05]
z = (np.sqrt(x**2 + y**2) + np.sin(x**2 + y**2))
hex_list = ['#0091ad', '#3fcdda', '#83f9f8', '#d6f6eb', '#fdf1d2', '#f8eaad', '#faaaae', '#ff57bb']

fig, ax = plt.subplots(1,1)
im = ax.imshow(z, cmap=get_continuous_cmap(hex_list))
fig.colorbar(im)
ax.yaxis.set_major_locator(plt.NullLocator()) # remove y axis ticks
ax.xaxis.set_major_locator(plt.NullLocator()) # remove x axis ticks