python: how to set the same colormap for 3 subplots

Question

I am using python to draw a figure with 3 subplots. I want to set the colormap to be hot for each subplot and my code is like:

fig, axes = plt.subplots(nrows=3, ncols=1, figsize=(20,15))
count = 0
for ax in axes.flat:
    count += 1
    if count == 1:
        im = ax.imshow(data_in_array, interpolation='nearest',vmin=0, vmax=150)
        ax.set_xticks(range(24))
        ax.set_xticklabels(('6','7','8','9','10','11','12','13','14','15','16','17','18','19','20','21','22','23','0','1','2','3','4','5'),fontsize=15)
        ax.set_yticks(range(8))
        ax.set_yticklabels(('Belltown', 'Downtown', 'Industrial District', 'Wallingford', 'University District', 'Capitol Hill', 'Lakecity','Ballard'),fontsize=15)
        ax.set_title('arriving hours of travel survey',fontsize=15)
        plt.hot()

    if count == 2:
        im = ax.imshow(data_out_array, interpolation='nearest',vmin=0, vmax=150)
        ax.set_xticks(range(24))
        ax.set_xticklabels(('6','7','8','9','10','11','12','13','14','15','16','17','18','19','20','21','22','23','0','1','2','3','4','5'),fontsize=15)
        ax.set_yticks(range(8))
        ax.set_yticklabels(('Belltown', 'Downtown', 'Industrial District', 'Wallingford', 'University District', 'Capitol Hill', 'Lakecity','Ballard'),fontsize=15)
        ax.set_title('leaving hours of travel survey',fontsize=15)
        plt.hot()

    if count == 3:
        im = ax.imshow(data_stay_array, interpolation='nearest',vmin=0, vmax=150)
        ax.set_xticks(range(24))
        ax.set_xticklabels(('6','7','8','9','10','11','12','13','14','15','16','17','18','19','20','21','22','23','0','1','2','3','4','5'),fontsize=15)
        ax.set_yticks(range(8))
        ax.set_yticklabels(('Belltown', 'Downtown', 'Industrial District', 'Wallingford', 'University District', 'Capitol Hill', 'Lakecity','Ballard'),fontsize=15)
        ax.set_title('stay hours of travel survey',fontsize=15)
        plt.hot()   


fig.subplots_adjust(right=0.8)
cbar_ax = fig.add_axes([0.75, 0.1, 0.03, 0.8])
fig.colorbar(im, cax=cbar_ax)
plt.show()

However, my plot is like:

The first one is not the hot colormap, any idea to fix that?

Answer 1

When you are plotting on the axes, you need to set the global colorbar before plotting. Hence, you need to have a plt.hot() call before the first ax.imshow().