from __future__ import print_function

fi = open('bi-decay.dat','r')
x = []
y = []

while(1):
	s = fi.readline()
	if s == '': break
	ss = s.split()
	time = float(ss[0])
	cnt = float(ss[1])
	x.append(time)
	y.append(cnt)

print (x,y)

y1, par = em.fitexp(x,y)
print (par)
