def calc_carbon_isotopes(pks, d13cstd, ks='Craig', d18ostd=23.5):
# get functions to tell us what the ratios of the standards
# should be over the course of the run
r45 = ratio_f(pks, r2=45, r1=44)
r46 = ratio_f(pks, r2=46, r1=44)
if r45 is None or r46 is None:
for pk in pks:
del pk.info['p-d13c']
return
for pk in pks:
# determine the peak areas for our peak and an interpolated standard
r45sam = pk.area(45) / pk.area(44)
r46sam = pk.area(46) / pk.area(44)
r45std = r45(pk.time())
r46std = r46(pk.time())
# determine the d13c value and assign it to the peaks info dict
d13c = delta13C_Santrock(r45sam, r46sam, d13cstd, \
r45std, r46std, ks, d18ostd)
pk.info['p-d13c'] = d13c
def test_delta13c():
r45sam, r46sam = 1.1399413, 1.5258049
d13cstd = -43.411
r45std, r46std = 1.1331231, 1.4058630
d13c = delta13C_Santrock(r45sam, r46sam, d13cstd, r45std, r46std, ks="Isodat", d18ostd=-21.097)
assert abs(d13c - (-40.30)) < 0.002
