I\'m trying to plot a matrix of values and would like to add gridlines to make the boundary between values clearer. Unfortunately, imshow decided to locate the tick marks in the
Code for solution as suggested by Serenity:
plt.figure()
im = plt.imshow(np.reshape(np.random.rand(100), newshape=(10,10)),
interpolation='none', vmin=0, vmax=1, aspect='equal')
ax = plt.gca();
# Major ticks
ax.set_xticks(np.arange(0, 10, 1))
ax.set_yticks(np.arange(0, 10, 1))
# Labels for major ticks
ax.set_xticklabels(np.arange(1, 11, 1))
ax.set_yticklabels(np.arange(1, 11, 1))
# Minor ticks
ax.set_xticks(np.arange(-.5, 10, 1), minor=True)
ax.set_yticks(np.arange(-.5, 10, 1), minor=True)
# Gridlines based on minor ticks
ax.grid(which='minor', color='w', linestyle='-', linewidth=2)
Resulting image: