I'm trying to work out the values on the x axis for the maximum value of y (ymax), ymax +0.5 and ymax - 0.5

Question

W = loadmat(\'W4dataP1.mat\', mat_dtype=True , squeeze_me=True )
locals().update({k :W[k]for k in [\'x\',\'y\',\'dy\']})
plt.errorbar(x,y,dy,fmt =\'r*\',label = \'Pl