The Preprocessor: PRESPARX

The command “presparx” can show the usage

$ presparx
presparx -o < Output File >
         -e : error estimation 
         -p : profile plot
         -v : generate vtk file

-o : the filename of the HDF data for SPARX input
-e : estimate the error of mass and the largest velocity dispersion
-p : generate a simple plot of the physical profile
-v : generate the VTK file for visualization purpose

grid.py for an example of a spherical 1D uniform grid

# Grid Type : SPH1D / SPH3D / CYL3D /REC3D / REC1D
GridType = 'SPH1D'
# spacing type : uniform / stretch
spacing = 'uniform'
# resolution of the radius
nr = 64
# inner radius (pc)
Rin = 0.0
# outer radius (pc)
Rout = 0.1

model.py for an example of Shu’s 1D collapsing cloud

# Model Type : Function / Constant / TABLE / ZEUS 
ModelType = 'Function'

# Molecule
molec = 'hco+'
# CMB temperature (Kelvin, outer B.C.)
T_cmb = 2.73
# inner Boundary condition
T_in = 0.0
# reference radius
r_ref = 0.01
# reference H2 number density (m^-3)
n_H2_ref = 1e10
# reference velocity (m/s)
V_ref = -200.0

# Gas Density (number/m^3)
def Density1D(r):
        n_H2 = n_H2_ref * ( r / r_ref )**-2.
        return n_H2
class model:
        def __init__(self,r):
                # Gas Density (number/m^3)
                self.n_H2 = Density1D(r)
                # Velocity (m/s)
                self.Vr = V_ref * ( r / r_ref )**-0.5
                # Temperature (Kelvin)
                self.T_k = 10.
                # turbulent speed (m/s)
                self.Vt = 200.
                # Molecular Abundance (fraction)
                self.X_mol = 1e-9
                # dust-to-gas ratio
                self.dust_to_gas = 0.01
                # Dust Temperature (Kelvin)
                self.T_d = self.T_k
                # dust kappa
                self.kapp_d = 'table,jena_thin_e5'

Command “presparx” and specify the model file name.
Append “-epv” to check out the error, profile plot, and the VTK file

$ presparx -o model -epv
Analytical Mass : 0.103706 Msun
Mass Error of the Gridding : 0.640518 %
Largest Velocity Dispersion to Turbulent Velocity : 1.512118
Largest Dispersion occurs at spatial index = 0
profile.png generated
visual.vtk generated
wrote out "model"

The options “-p” and “-v” would generate a figure ‘profile.png’ and a VTK file ‘visual.vtk’. The profile of this model is shown as below