I have created a set of heatmaps in a 6x3 subplot grid. As you can see, I added a shared color bar in the last row that spans over all columns (I used a grid spec to realize this). While iterating through the rows and columns, I made sure that the Y tick labels are only rendered for the first column and the X tick labels only for the last row. I am already pretty happy with the results, except for one thing: Due to the Y tick labels from subplots of the first column, the color bar also starts where the Y tick labels start. While this is great for the subplots that contain the actual heatmaps, it is unnecessary for the color bar. I would like to remove this padding on the left side and if possible center the color bar in the middle of the last row. I tried various approaches like disabling the ticks for the color bar axis using cax.set_yticks(ticks=[]) or removing the margin with cax.set_xmargin(0) but nothing worked so far. fig = plt.figure(figsize=(12, 13), layout="constrained") def render_heatmaps(): # Create a figure with multiple subplots nrows = ( len(domain_knowledge["DS1: Automotive"]) + 2 ) # usually 4 + 2 for infobox and color bar ncols = len(domain_knowledge.keys()) # usually 3 gs = fig.add_gridspec(nrows, ncols) # Adjust the width ratios gs.set_height_ratios([0.7, 1, 1, 1, 1, 0.1]) gs.hspace = 0.07 gs.wspace = 0.02 # Render infobox ax_text: Axes = fig.add_subplot(gs[0, :]) render_infobox(ax_text) # Create a colorbar based on the min/max values that are in all datasets (contingency matrices for each study object) norm = mcolors.Normalize(vmin=np.min(datasets), vmax=np.max(datasets)) colors = ScalarMappable(norm, cmap="GnBu") for row in range(nrows - 2): for col in range(ncols): axis = fig.add_subplot(gs[row + 1, col]) # Render the combined heatmap sns.heatmap( datasets[col * 4 + row], annot=True, cmap=colors.cmap, # only show the y labels on the first column yticklabels=(categories_necessity[:nec_range] if col == 0 else False), # only show the x labels on the last row xticklabels=( categories_temporality[:temp_range] if row + 1 == nrows - 2 else False ), ax=axis, cbar=False, # uses a combined colorbar ) axis.tick_params(axis="y", labelrotation=0) axis.set_title(label=f"S{col*4+row}") # create a combined colorbar cax = fig.add_subplot(gs[nrows - 1, :]) # Use all columns for the colorbar cax.set_xmargin(0) fig.colorbar( colors, cax=cax, orientation="horizontal", ) cax.set_title("Number of Study Responses") Continue reading...
