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 calcGalacticCoordinates(angMomGroup=None, center ='pot'):
'''Assigns particles a position in the galactic coordinate system. galVelocity = (v+Hr). angMomGroup'''
#===========================================================================
# --Overview--
# 1.Form transformation matrix
# 2.Translate the coordinates to the center of the galaxy (or COM velocity)
# 3.Rotate the coordinate system to be aligned with the angular momentum vector
# 4.Write information to vector attributes
#===========================================================================
if ((angMomGroup in charm.getGroups())==False) & (angMomGroup!=None):
print "Group does not exist, please try again."
return
##############################
# Actual Routine
##############################
if (angMomGroup==None):
angMomGroup = 'angMomGroup'
cnt = findcenter.findCenter(method=center)
virialRadius = virialgroup.getVirialGroup()
charm.createGroupAttributeSphere('angMomGroup', 'All', 'position', cnt[0], cnt[1], cnt[2], virialRadius*quesoConfig.rgalFraction)
charm.createGroup_Family('angMomGroup', 'angMomGroup', 'gas')
charm.createGroup_AttributeRange('angMomGroup', 'angMomGroup', 'temperature', 0, quesoConfig.coldGasTemp)
else:
cnt = findcenter.findCenter(group2=angMomGroup,method=center)
angmom.getAngMomVector(group=angMomGroup,center=center)
# Transformation Matrix
galZ = vectormath.normalizeVector(angmom.getAngMomVector(group=angMomGroup,center=center))
galX = vectormath.normalizeVector(vectormath.crossVectors((0,1,0),galZ))
galY = vectormath.normalizeVector(vectormath.crossVectors(galZ,galX))
transMatrix = (galX,
galY,
galZ)
fHubble = quesoConfig.fHubble0*math.sqrt(quesoConfig.omega0/charm.getTime()**3+(1-quesoConfig.omega0))
# Galactic Position
charm.createVectorAttribute('star','galPosition')
charm.createVectorAttribute('gas', 'galPosition')
charm.createVectorAttribute('dark','galPosition')
param = (cnt, transMatrix)
charm.runLocalParticleCodeGroup('All', calcGalPosition, param)
# Galactic velocity
vCM=angmom.getVelCM(angMomGroup)
param = (cnt, transMatrix,vCM, fHubble)
charm.createVectorAttribute('star','galVelocity')
charm.createVectorAttribute('gas', 'galVelocity')
charm.createVectorAttribute('dark','galVelocity')
charm.runLocalParticleCodeGroup('All', calcGalVelocity, param)
return
def getHalfMassRadius(group, center='pot') :
"""Returns the current stellar half mass radius."""
#get the current galactic stellar mass
rgal = 0.1*virialgroup.getVirialGroup()
center = findcenter.findCenter(group2=group,method=center)
halfMass = getFamilyAttributeSum(center,rgal,'star','mass')/2.0
if (halfMass == 0 ):
print "Halfmass is zero inside rgal. Are there stars inside rgal yet?."
return (0,0)
#Bisection Method to locate half mass
epsilon = .01
count = 0
maxIterations = 50
a = charm.getTime()
leftr = .1/(a*quesoConfig.kpcunit)
rightr = 50/(a*quesoConfig.kpcunit)
midpoint = (leftr + rightr)/2.0
leftMass = getFamilyAttributeSum(center,leftr ,'star','mass')-halfMass #Initialize values
rightMass = getFamilyAttributeSum(center,rightr ,'star','mass')-halfMass #offset to find root
midMass = getFamilyAttributeSum(center,midpoint,'star','mass')-halfMass #offset so we can find root
#Bisection to find halfmass radius using initialMass and mass
#Run until values converge within epsilon or reach max count
while (count<maxIterations) and (math.fabs((leftMass-rightMass)/halfMass) > epsilon*2.0):
midpoint = (leftr + rightr)/2.0
#if (math.fabs(leftMass-rightMass)/halfMass < 4*epsilon):break
leftMass = getFamilyAttributeSum(center,leftr ,'star','mass')-halfMass #Initialize values
rightMass= getFamilyAttributeSum(center,rightr ,'star','mass')-halfMass #offset to find root
midMass = getFamilyAttributeSum(center,midpoint,'star','mass')-halfMass #offset so we can find root
#print str((leftMass,midMass,rightMass)) + " " + str(math.fabs(leftMass-rightMass)/halfMass) +str((leftr,midpoint,rightr))
if (leftMass*midMass<0) : rightr = midpoint
elif (rightMass*midMass<0): leftr = midpoint
elif (midMass==0) : break
elif (leftMass*midMass>0) and (rightMass*midMass>0):
print "\nStellar half mass radius will not converge. Try larger bounds."
return
count += 1
#Don't get stuck in a loop
if (count==maxIterations):
print "\nDid not converge in " + str(maxIterations) + " iterations. Try smaller bounds or raise epsilon in source."
return
resultVec=midpoint #already in units of kpc taking into account the expansion factor
#print resultVec[i]
return resultVec