def sfh(sim, filename=None, massform=True, clear=False, legend=False,
subplot=False, trange=False, bins=100, **kwargs):
'''
star formation history
**Optional keyword arguments:**
*trange*: list, array, or tuple
size(t_range) must be 2. Specifies the time range.
*bins*: int
number of bins to use for the SFH
*massform*: bool
decides whether to use original star mass (massform) or final star mass
*subplot*: subplot object
where to plot SFH
*legend*: boolean
whether to draw a legend or not
*clear*: boolean
if False (default), plot on the current axes. Otherwise, clear the figure first.
By default, sfh will use the formation mass of the star. In tipsy, this will be
taken from the starlog file. Set massform=False if you want the final (observed)
star formation history
**Usage:**
>>> import pynbody.plot as pp
>>> pp.sfh(s,linestyle='dashed',color='k')
'''
import matplotlib.pyplot as pyplot
if subplot:
plt = subplot
else:
plt = pyplot
if "nbins" in kwargs:
bins = kwargs['nbins']
if 'nbins' in kwargs:
bins = kwargs['nbins']
del kwargs['nbins']
if ((len(sim.g)>0) | (len(sim.d)>0)): simstars = sim.star
else: simstars = sim
if trange:
assert len(trange) == 2
else:
trange = [simstars['tform'].in_units(
"Gyr").min(), simstars['tform'].in_units("Gyr").max()]
binnorm = 1e-9 * bins / (trange[1] - trange[0])
trangefilt = filt.And(filt.HighPass('tform', str(trange[0]) + ' Gyr'),
filt.LowPass('tform', str(trange[1]) + ' Gyr'))
tforms = simstars[trangefilt]['tform'].in_units('Gyr')
if massform:
try:
weight = simstars[trangefilt][
'massform'].in_units('Msol') * binnorm
except (KeyError, units.UnitsException):
warnings.warn(
"Could not load massform array -- falling back to current stellar masses", RuntimeWarning)
weight = simstars[trangefilt]['mass'].in_units('Msol') * binnorm
else:
weight = simstars[trangefilt]['mass'].in_units('Msol') * binnorm
if clear:
plt.clf()
sfhist, thebins, patches = plt.hist(tforms, weights=weight, bins=bins,
histtype='step', **kwargs)
if not subplot:
# don't set the limits
#plt.ylim(0.0, 1.2 * np.max(sfhist))
plt.xlabel('Time [Gyr]', fontsize='large')
plt.ylabel('SFR [M$_\odot$ yr$^{-1}$]', fontsize='large')
else:
plt.set_ylim(0.0, 1.2 * np.max(sfhist))
# Make both axes have the same start and end point.
if subplot:
x0, x1 = plt.get_xlim()
else:
x0, x1 = plt.gca().get_xlim()
# add a z axis on top if it has not been already done by an earlier plot:
from pynbody.analysis import pkdgrav_cosmo as cosmo
c = cosmo.Cosmology(sim=sim)
old_axis = pyplot.gca()
pz = plt.twiny()
labelzs = np.arange(5, int(sim.properties['z']) - 1, -1)
times = [13.7 * c.Exp2Time(1.0 / (1 + z)) / c.Exp2Time(1) for z in labelzs]
pz.set_xticks(times)
pz.set_xticklabels([str(x) for x in labelzs])
pz.set_xlim(x0, x1)
pz.set_xlabel('$z$')
pyplot.sca(old_axis)
if legend:
plt.legend(loc=1)
if filename:
logger.info("Saving %s", filename)
plt.savefig(filename)
return array.SimArray(sfhist, "Msol yr**-1"), array.SimArray(thebins, "Gyr")
def getTime(z, sim):
c = cosmo.Cosmology(sim=sim)
return 13.7 * c.Exp2Time(1.0 / (1 + z)) / c.Exp2Time(1)
