Exemplo n.º 1
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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
Exemplo n.º 2
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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)
Exemplo n.º 3
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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
Exemplo n.º 4
0
 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
Exemplo n.º 5
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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
Exemplo n.º 6
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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    
Exemplo n.º 7
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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