Geometry

Spatial grids

class jjmodel.geometry.Grid(zmax, dz, rmax, rnum, **kwargs)[source]

Class for creating (r,l,z) grids (e.g. for the Solar neighbourhood modeling).

__init__(zmax, dz, rmax, rnum, **kwargs)[source]

Initialization.

Parameters

  • zmax (scalar) -- Maximal height, pc.

  • dz (scalar) -- Step in height, pc.

  • rmax (scalar) -- Maximal distance from z-axis in xy-plane, pc.

  • rnum (int) -- Number of bins along r axis (in xy plane).

  • rlog (boolean) -- Optional. If True, binning along r axis is in log space.

  • dl (scalar) -- Optional. Step in angle (longitude), deg.

ind_part(zcent, zwidth)[source]

Returns indices corresponding to a z-slice.

Parameters

  • zcent (scalar) -- Mean z of the slice, pc.

  • zwidth (scalar) -- Half-width of the slice, pc.

Returns

Index array of the full z-grid corresponding to the selected slice.

Return type

1d-array

indl(lmin, lmax, **kwargs)[source]

Generates indices of the part of l-array (indices correspond to the full l-grid).

Parameters

  • lmin (scalar) -- Minimal longitude, deg.

  • lmax (scalar) -- Maximal longitude, deg.

Dl

Optional. Step in angle, deg.

Returns

Index array.

Return type

1d-array

indr(rmin, rmax)[source]

Generates indices of the part of r-array (indices correspond to the full r-grid).

Parameters

  • rmin (scalar) -- Minimal r, pc.

  • rmax (scalar) -- Maximal r, pc.

Returns

Index array.

Return type

1d-array

indz_full()[source]

Generates indices of the full z-grid.

Returns

Index array corresponding to the created z-grid.

Return type

1d-array

make()[source]

Puts all grid elements into a namedtuple.

Returns

Grid along z and r axes (optionally also in angle l).

Return type

namedtuple

Modeling volumes

class jjmodel.geometry.Volume(p, a)[source]

Class for calculating volumes of the different spatial cells.

__init__(p, a)[source]

Class instance is initialized by collections of parameters and useful arrays.

Parameters

  • p (namedtuple) -- Set of model parameters from the parameter file.

  • a (namedtuple) -- Collection of the fixed model parameters, useful quantities, and arrays.

local_cylinder(r_min, r_max, z_min, z_max)[source]

Returns z-grid with volume of the cells for the local cylinder with an inner hole. For testing, do:

import numpy as np
from jjmodel.input_ import p,a
from jjmodel.geometry import Volume

V = Volume(p,a)
v2 = V.local_cylinder(100,800,0,500)
print(np.sum(v2[0])/(2*np.pi*(800**2-100**2)*500))
Parameters

  • r_min (scalar) -- Inner radius of the cylinder, pc.

  • r_max (scalar) -- Outer radius of the cylinder, pc.

  • z_min (scalar) -- Minimal absolute z, pc.

  • z_max (scalar) -- Maximal absolute z, pc.

Returns

Three quantities are calculated:

  • z-grid with volumes of the cells, \(\mathrm{pc}^3\). If the outer radius of the cylinder is larger than the model radial resolution p.dR, then the cylinder will be splitted over several radial bins, and z-grid with volumes will be given separately for each radial bin.

  • Indices of the radial bins for which z-grids are calculated (to get radii, use these indices with a.R array).

  • Reference line with information about the input parameters.

Return type

[array-like, array-like, str]

local_sphere(r_min, r_max)[source]

Returns z-grid with volume of the cells for the local sphere with an inner hole. For testing, do:

import numpy as np
from jjmodel.input_ import p,a
from jjmodel.geometry import Volume

V = Volume(p,a)
v1 = V.local_sphere(0,850) 
print(np.sum(v1[0])/(4/3*np.pi*850**3))
Parameters

  • r_min (scalar) -- Inner radius of the spherical shell, pc.

  • r_max (scalar) -- Outer radius of the spherical shell, pc.

Returns

Three quantities are calculated:

  • z-grid with volumes of the cells, \(\mathrm{pc}^3\). If the outer radius of the sphere is larger than the model radial resolution p.dR, then the sphere will be splitted over several radial bins, and z-grid with volumes will be given separately for each radial bin.

  • Indices of radial bins for which z-grids are calculated (to get the radii, use these indices with a.R array).

  • Reference line with information about the input parameters.

Return type

[array-like, array-like, str]

none()[source]

Useful when the volume does not need to be taken into account, but equation is kept general with the volume term. In this case, the volume array can be simply filled with ones.

Retrun

z-grid array of the length a.n filled with ones.

Return type

1d-array

rphiz_box(R_min, R_max, dphi, z_min, z_max)[source]

Returns volume z-grid for the 'box' in the Galactic cylindrical coordinates (R,:math:phi,z). For testing, do:

import numpy as np
from jjmodel.input_ import p,a
from jjmodel.geometry import Volume

V = Volume(p,a)
v3 = V.rphiz_box(8.15,8.25,360,100,250)
print(np.sum(v3[0])/(2*np.pi*(8250**2-8150**2)*150))
Parameters

  • R_min (scalar) -- Minimal Galactocentric radius, kpc.

  • R_max (scalar) -- Maximal Galactocentric radius, kpc.

  • dphi (scalar) -- Galactocentric(? not sure how it's called..) angle, deg.

  • z_min (scalar) -- Minimal absolute z, pc.

  • z_max (scalar) -- Maximal absolute z, pc.

Returns

Three quantities:

  • z-grid with volumes of the cells, \(\mathrm{pc}^3\). If the radial span of the volume is larger than the model radial resolution p.dR, then it will be splitted over several radial bins, and z-grid with volumes will be given separately for each radial bin.

  • Indices of the radial bins for which z-grids are calculated (to get radii, use these indices with a.R array).

  • Reference line with information about the input parameters.

Return type

[array-like, array-like, str]

zcut(v, zlim)[source]

Fills z-cells laying outside of the chosen range with zeros.

Parameters

  • v (1d-array) -- z-grid with volume of the cells. z-grid has length a.n (absolute z from 0 to p.zmax with a step of p.dz).

  • zlim (list) -- Minimal and maximal absolute z.

Returns

z-grid with volume of the cells.

Return type

1d-array