def getVelCM(group):
"""Finds and returns a COM velocity vector for a given group."""
mass = charm.getAttributeSum(group, 'gas', 'mass')
mass += charm.getAttributeSum(group, 'star', 'mass')
mass += charm.getAttributeSum(group, 'dark', 'mass')
vmoment = charm.reduceParticle(group, centMassVelMap, centMassReduce, None)[0][1:4]
vcm = (vmoment[0]/mass, vmoment[1]/mass, vmoment[2]/mass)
return vcm #return the COM velocity vector
def getEpsilonDist(group='gal', nBins=50, epsCut=2., center='pot'):
"""Returns a histogram of dimension 2 x nbins of stellar epsilons (jz/jcirc) and mass-fraction. epsCut defines the histogram bound in both directions. Center can be either 'pot' or 'com'"""
numRotBins = 400 #number of points at which we linearly interpolate
radiusVCM = 0.25 #fraction of group radius to use when calculating COM velocity
radiusAngMom = 0.25 #fraction of group radius to use when calculating stellar angular momentum
a = charm.getTime()
if ((group in charm.getGroups()==False)) & (group !='gal'):
print "Group does not exist, please try again."
return
if (group == 'gal'):
rgal = quesoConfig.rgalFraction*virialgroup.getVirialGroup()
center=findcenter.findCenter(group2='virialGroup', method=center)
charm.createGroupAttributeSphere('gal', 'All', 'position', center[0], center[1], center[2], rgal)
else:
center=findcenter.findCenter(group2=group, method=center)
# Find maximum radius
charm.createGroup_Family('tmp',group,'star')
maxRad = getgroupradius.getGroupRadius('tmp', center)
massDist = [0]*(numRotBins+1)
rad = [0]*(numRotBins+1)
radialStep = maxRad/numRotBins
#populate mass bins
for i in range(numRotBins+1):
charm.createGroupAttributeSphere('tmp', 'All', 'position', center[0], center[1], center[2], radialStep*i)
massDist[i] = charm.getAttributeSum('tmp','star','mass')
massDist[i] += charm.getAttributeSum('tmp','dark','mass')
massDist[i] += charm.getAttributeSum('tmp','gas' ,'mass')
#Note: I tried shells instead of spheres and it made no real difference.
rad[i] = radialStep*i
vCM = getVelCMStars(center2=center, radius=radiusVCM*maxRad) #COM velocity
angMomVec = getNormalStarAngMom(center2=center, radius=radiusAngMom*maxRad, comVel=vCM) #Ang Mom Velocity
#vCM = getVelCMStars(center2=center, radius=10/(a*quesoConfig.kpcunit)) #COM velocity
#angMomVec = getNormalStarAngMom(center2=center, radius=6/(a*quesoConfig.kpcunit), comVel=vCM) #Ang Mom Velocity
param = (center, vCM, angMomVec, maxRad, numRotBins,massDist, nBins,epsCut)
charm.createGroupAttributeSphere('tmp', 'All', 'position', center[0], center[1], center[2], maxRad)
charm.createGroup_Family('tmp',group,'star')
#calc total stellar mass for mass weighted average
reduceResult = charm.reduceParticle('tmp', mapEpsilon, reduceEpsilon, param)
sMass = charm.getAttributeSum('tmp','star', 'mass')
epsilonDist = [0]*nBins
eps = [0]*nBins
for i in range(nBins): eps[i] = -epsCut+ 2*epsCut/nBins*(i)
for i in range(len(reduceResult)):
try:
bin = reduceResult[i][0]
epsilonDist[bin] = reduceResult[i][1]/sMass #return the mass fraction
except:{}
return (eps, epsilonDist)
def getFamilyAttributeSum(center2,r,family,attribute):
"""Integrates attributes of a given family over a given sphere."""
charm.createGroupAttributeSphere('group', 'All', 'position', center2[0], center2[1], center2[2], r)
charm.createGroup_Family('group','group',family)
sum = charm.getAttributeSum('group', family, attribute)
charm.deleteGroup('group')
return sum
def getGalDensity(center2, r):
charm.createGroupAttributeSphere(virialGroup, "All", "position", center[0], center[1], center[2], r)
totMass = 0.0
for fam in charm.getFamilies():
totMass += charm.getAttributeSum(virialGroup, fam, "mass")
v = (4 * math.pi / 3.0) * r ** 3
density = totMass / v
return density
def getAngMomVector(group, center='pot'):
"""Returns specific angular momentum vectors in physical units. Center can be 'pot' or 'com'"""
if ((group in charm.getGroups())==False):
print "Group does not exist, please try again."
return
def multVectorScalar(scalar,vector):
return (vector[0]*scalar,vector[1]*scalar,vector[2]*scalar)
center = findcenter.findCenter(group2=group,method=center)
#find COM Velocity
vCM=getVelCM(group)
angMomVector = charm.reduceParticle(group, getParticleAngMomentum, sumAngMomentum, [center,vCM])
mass = charm.getAttributeSum(group, 'gas', 'mass')
mass += charm.getAttributeSum(group, 'star', 'mass')
mass += charm.getAttributeSum(group, 'dark', 'mass')
unitConvert = quesoConfig.kpcunit*quesoConfig.velocityunit #masses are divided out anyway.
#Convert this into a specific angular momentum 3-vector
angMomVector = multVectorScalar(unitConvert/mass, (angMomVector[0][1] ,angMomVector[0][2] ,angMomVector[0][3]))
return angMomVector
def getVelCMStars(center2, radius):
"Returns the vector for the center of mass velocity of a group of stars defined by center2 coordinates and a radius."
charm.createGroupAttributeSphere('tmpGal', 'All', 'position', center2[0], center2[1], center2[2], radius) #use cmVelCompare2.py to choose length
charm.createGroup_Family('tmpStarGroup', 'tmpGal', 'star') #select star particles only
massStar = charm.getAttributeSum('tmpGal', 'star', 'mass')
mass = massStar #calculate total mass
vmomentStar = charm.reduceParticle('tmpStarGroup', centMassVelMap, centMassReduce, None)
vmoment = [vmomentStar[0][1],vmomentStar[0][2],vmomentStar[0][3]]
vcm = (vmoment[0]/mass, vmoment[1]/mass, vmoment[2]/mass)
#Clean up
charm.deleteGroup('tmpGal')
charm.deleteGroup('tmpStarGroup')
return vcm #return the COM velocity vector
def boxstat(group, family='all') :
"""Print statistics for a group as in the tipsy boxstat command
Arguments are group and family
Return physical parameters of particles:
number, mass, center of box, size of box, center of mass,
center of mass's velocity, angular momentum vector.
Format output to say if gas, dark, star, baryon, or all.
Check error cases: Bad input, Not a proper data type, Box not loaded."""
import charm
# check if simulation loaded
if charm.getGroups() == None :
raise StandardError('Simulation not loaded')
# There is a potential issue with the capitalization of "all" being mixed
# in different implementations. Take either.
if family == 'All':
family = 'all'
if group == 'all':
group = 'All'
# Prepare values based on selected family
if family == 'all':
nPartGas = charm.getNumParticles(group, 'gas')
nPartDark = charm.getNumParticles(group, 'dark')
nPartStar = charm.getNumParticles(group, 'star')
mass = charm.getAttributeSum(group, 'gas', 'mass')
mass += charm.getAttributeSum(group, 'dark', 'mass')
mass += charm.getAttributeSum(group, 'star', 'mass')
bBox = list(charm.getAttributeRangeGroup(group, 'gas', 'position'))
bBoxTmp = charm.getAttributeRangeGroup(group, 'dark', 'position')
bBox[0] = map(lambda x, y : min(x,y), bBox[0], bBoxTmp[0])
bBox[1] = map(lambda x, y : max(x,y), bBox[1], bBoxTmp[1])
bBoxTmp = charm.getAttributeRangeGroup(group, 'star', 'position')
bBox[0] = map(lambda x, y : min(x,y), bBox[0], bBoxTmp[0])
bBox[1] = map(lambda x, y : max(x,y), bBox[1], bBoxTmp[1])
groupfamname = group
elif family == 'baryon':
nPartGas = charm.getNumParticles(group, 'gas')
nPartStar = charm.getNumParticles(group, 'star')
mass = charm.getAttributeSum(group, 'gas', 'mass')
mass += charm.getAttributeSum(group, 'star', 'mass')
bBox = list(charm.getAttributeRangeGroup(group, 'gas', 'position'))
bBoxTmp = charm.getAttributeRangeGroup(group, 'star', 'position')
bBox[0] = map(lambda x, y : min(x,y), bBox[0], bBoxTmp[0])
bBox[1] = map(lambda x, y : max(x,y), bBox[1], bBoxTmp[1])
groupfamname = group
else :
nPart = charm.getNumParticles(group, family)
mass = charm.getAttributeSum(group, family, 'mass')
bBox = charm.getAttributeRangeGroup(group, family, 'position')
groupfamname = group + 'FAM' + family
charm.createGroup_Family(groupfamname, group, family)
# Derive box properties
size = map(lambda min, max : max - min, bBox[0], bBox[1])
center = map(lambda min, max : 0.5*(max + min), bBox[1], bBox[0])
mmoment = charm.reduceParticle(groupfamname, centmassmap, centmassreduce, None)
cm = [mmoment[0][1]/mass, mmoment[0][2]/mass, mmoment[0][3]/mass]
vmoment = charm.reduceParticle(groupfamname, centmassVelmap, centmassreduce, None)
vcm = [vmoment[0][1]/mass, vmoment[0][2]/mass, vmoment[0][3]/mass]
angmom1 = charm.reduceParticle(groupfamname, angmomMap, centmassreduce, None)
# Apply parallel axis theorem and make specific
angmom = [0,0,0]
angmom[0] = (angmom1[0][1] - mass*(cm[1]*vcm[2] - cm[2]*vcm[1]))/mass
angmom[1] = (angmom1[0][2] - mass*(cm[2]*vcm[0] - cm[0]*vcm[2]))/mass
angmom[2] = (angmom1[0][3] - mass*(cm[0]*vcm[1] - cm[1]*vcm[0]))/mass
# Write output header according to type of particles
if family == 'all' :
print 'number of dark, gas and star particles =', nPartDark, nPartGas, nPartStar
elif family == 'baryon' :
print 'number of baryon particles =', (nPartGas + nPartStar)
else:
print 'number of', family, 'particles =', nPart
# Write physical parameters
print 'mass =', mass
print 'center coordinates =', center
print 'size =', size
print 'center of mass coordinates =', cm
print 'center of mass velocity =', vcm
print 'angular momentum vector =', angmom