def annotate_subplot(ax, ncols=<NUM_LIT:1>, nrows=<NUM_LIT:1>, letter='<STR_LIT:a>',<EOL>linear_offset=<NUM_LIT>, fontsize=<NUM_LIT:8>):
ax.text(-ncols*linear_offset, <NUM_LIT:1>+nrows*linear_offset, letter,<EOL>horizontalalignment='<STR_LIT>',<EOL>verticalalignment='<STR_LIT>',<EOL>fontsize=fontsize, fontweight='<STR_LIT>',<EOL>transform=ax.transAxes)<EOL>
add a subplot annotation number