matplotlib - I cannot figure out how to spread out the space on the y axis for my scatterplot in Python -

i entered code x, y, , size defined variables created earlier. problem points bunched , want stretch out y-axis.

plt.scatter(rets.mean(),rets.std(),s = area) plt.xlabel('expected return') plt.ylabel('risk') 

for example, right y-axis goes -0.005 0.04 in increments of 0.005, how adjust count in increments of 0.0025?

import matplotlib.pyplot plt import matplotlib.ticker mticks  fig, ax = plt.subplots()  ax.set_ylim((-.005, .04)) ax.yaxis.set_major_locator(mticks.multiplelocator(.0025))