import lmfit
import numpy as np

pv = lmfit.models.PseudoVoigtModel()

def fitPeak(x,y,autorange=False):
  if autorange:
    # find fwhm
    idx = np.ravel(np.argwhere( y<y.max()/2 ))
    # find first crossing
    p1 = idx[idx<np.argmax(y)][-1]
    p2 = idx[idx>np.argmax(y)][0]
    c = int( (p1+p2)/2 )
    dp = int( np.abs(p1-p2) )
    idx = slice(c-dp,c+dp)
    x = x[idx]
    y = y[idx]
  pars = pv.guess(y,x=x)
  ret  = pv.fit(y,x=x,params=pars)
  return ret