seaborn heatmap parameters
# seaborn heatmap best parameter
plt.figure(figsize=(20,8))
sns.heatmap(corr, vmax=1, vmin=-1, center=0,
linewidth=.5,square=True, annot = True,
annot_kws = {'size':8},fmt='.1f', cmap='BrBG_r', ax=ax1, # ax: use this when using subplot
cbar_kws = dict(use_gridspec=False,location="top", shrink=0.9)) # cbar_kws: for positioning cbar and "shrink" for reducing cbar size
plt.title('Correlation')
plt.show()