pyharm.crd

Module to work with the coordinates of evaluation points/cells:

• defines the following classes pyharm.crd.PointSctr, pyharm.crd.PointGrid, pyharm.crd.PointGridGL, pyharm.crd.PointGridDH1, pyharm.crd.PointGridDH2, pyharm.crd.CellSctr and pyharm.crd.CellGrid,

• computes Gauss–Legendre and Driscoll–Healy quadrature grids.

Note

This documentation is written for double precision version of PyHarm.

class pyharm.crd.PointSctr(npoint, data)

Class for scattered points.

For details, refer to charm_crd.

To create a PointSctr class instance, always use one of the following factory methods:

• from_garbage(),

• from_zeros(),

• from_arrays().

Example

• Create an instance with 5 scattered points and all array elements initialized to zero:

  >>> import pyharm as ph
  >>> grd = ph.crd.PointSctr.from_zeros(5)
  

• Create an instance with 3 scattered points with latitudes, longitudes and spherical radii taken from numpy arrays:

  >>> import numpy as np
  >>> import pyharm as ph
  >>> lat  = np.array([0.1, 0.2, 0.3])
  >>> lon  = np.array([0.5, 0.6, 0.7])
  >>> r    = np.array([1.1, 1.2, 1.3])
  >>> sctr = ph.crd.PointGrid.from_arrays(lat, lon, r)
  

Parameters:

• npoint (integer) – Number of scattered points

• data (None, 0 or tuple) –

  Determines the way of initializing array elements:

  • None to not initialize array elements (malloc in C),

  • 0 to set all array elements to zero (calloc in C),

  • (lat, lon, r) to define the object’s latitudes, longitudes and spherical radii, respectively. The lat, lon and r variables must be numpy floating point arrays of dimension 1. The number of elements in lat, lon and r must match.

Note

Once a PointSctr class instance is created, its attributes are not writeable, but all array elements are writeable.

classmethod from_garbage(npoint)

Returns a PointSctr class instance with uninitialized array elements (malloc in C).

Parameters:

npoint (integer) – Number of scattered points

Returns:

out – PointSctr class instance

Return type:

PointSctr

classmethod from_zeros(npoint)

Returns a PointSctr class instance with all array elements initialized to zero (calloc in C).

Parameters:

npoint (integer) – Number of scattered points

Returns:

out – PointSctr class instance

Return type:

PointSctr

classmethod from_arrays(lat, lon, r)

Returns a PointSctr class instance with spherical latitudes, longitudes and spherical radii taken from lat, lon and r, respectively.

Parameters:

• lat (numpy array of floating points) – Spherical latitudes

• lon (numpy array of floating points) – Spherical longitudes

• r (numpy array of floating points) – Spherical radii

Returns:

out – PointSctr class instance

Return type:

PointSctr

property lat

Spherical latitudes.

property lon

Spherical longitudes.

property npoint

Total number of points.

property owner

Refer to pyharm.shc.Shc for documentation.

property r

Spherical radii.

class pyharm.crd.PointGrid(nlat, nlon, data)

Class for custom point grids.

For details, refer to charm_crd.

To create a PointGrid class instance, always use one of the following factory methods:

• from_garbage(),

• from_zeros(),

• from_arrays().

Examples

• Create an instance with 5 grid latitudes and 10 grid longitudes and initialize all array elements to zero:

  >>> import ph
  >>> grd = ph.crd.PointGrid.from_zeros(5, 10)
  

• Create an instance with grid latitudes, longitudes and spherical radii taken from numpy arrays:

  >>> import numpy as np
  >>> import pyharm as ph
  >>> lat = np.array([0.1, 0.2, 0.3])
  >>> lon = np.array([0.5, 0.6, 0.7, 0.8, 0.9])
  >>> r   = np.array([1.1, 1.2, 1.3])
  >>> grd = ph.crd.PointGrid.from_arrays(lat, lon, r)
  

Parameters:

• nlat (integer) – Number of grid latitudes

• nlon (integer) – Number of grid longitudes

• data (None, 0 or tuple) –

  Determines the way of initializing array elements:

  • None to not initialize array elements (malloc in C),

  • 0 to set all array elements to zero (calloc in C),

  • (lat, lon, r) to define the object’s latitudes, longitudes and spherical radii, respectively. The lat, lon and r variables must be numpy floating point arrays of the dimension 1. The shape of lat and r must match.

Note

Once a PointGrid class instance is created, its attributes are not writeable, but all array elements are writeable.

classmethod from_garbage(nlat, nlon)

Returns a PointGrid class instance with uninitialized array elements (malloc in C).

Parameters:

• nlat (integer) – Number of grid latitudes

• nlon (integer) – Number of grid longitudes

Returns:

out – PointGrid class instance

Return type:

PointGrid

classmethod from_zeros(nlat, nlon)

Returns a PointGrid class instance with all array elements initialized to zero (calloc in C).

Parameters:

• nlat (integer) – Number of grid latitudes

• nlon (integer) – Number of grid longitudes

Returns:

out – PointGrid class instance

Return type:

PointGrid

classmethod from_arrays(lat, lon, r)

Returns a PointGrid class instance with spherical latitudes, longitudes and spherical radii taken from lat, lon and r, respectively.

Parameters:

• lat (numpy array of floating points) – Spherical latitudes

• lon (numpy array of floating points) – Spherical longitudes

• r (numpy array of floating points) – Spherical radii

Returns:

out – PointGrid class instance

Return type:

PointGrid

property lat

Spherical latitudes.

property lon

Spherical longitudes.

property npoint

Total number of points.

property owner

Refer to pyharm.shc.Shc for documentation.

property r

Spherical radii.

class pyharm.crd.PointGridGL(nmax, r=np.float64(1.0))

Class for Gauss–Legendre point grids.

For details, refer to charm_crd.

Create a PointGridGL class instance like this:

>>> import pyharm as ph
>>> gl = ph.crd.PointGridGL(10)

Parameters:

• nmax (integer) – Maximum harmonic degree associated with the quadrature grid

• r (floating point) – Spherical radius of grid meridians, optional. Default value is 1.0.

Note

Once a PointGridGL class instance is created, neither its attributes nor its array elements are writeable.

property w

Integration weights on the unit sphere.

property nmax

Maximum harmonic degree associated with the quadrature grid points.

static shape(nmax)

Returns the number of latitudes nlat and the number of longitudes nlon of the Gauss-Legendre grid that corresponds to the maximum harmonic degree nmax.

Parameters:

nmax (integer) – Maximum harmonic degree of the Gauss-Legendre grid

Returns:

• nlat (integer) – Number of latitudes

• nlon (integer) – Number of longitudes

property lat

Spherical latitudes.

property lon

Spherical longitudes.

property npoint

Total number of points.

property owner

Refer to pyharm.shc.Shc for documentation.

property r

Spherical radii.

class pyharm.crd.PointGridDH1(nmax, r=np.float64(1.0))

Class for non-equiangular Driscoll–Healy point grids.

For details, refer to charm_crd.

Create a PointGridDH1 class instance like this:

>>> import pyharm as ph
>>> gl = ph.crd.PointGridDH1(10)

Parameters:

• nmax (integer) – Maximum harmonic degree associated with the quadrature grid

• r (floating point) – Spherical radius of grid meridians, optional. Default value is 1.0.

Note

Once a PointGridDH1 class instance is created, neither its attributes nor its array elements are writeable.

property w

Integration weights on the unit sphere.

property nmax

Maximum harmonic degree associated with the quadrature grid points.

static shape(nmax)

Returns the number of latitudes nlat and the number of longitudes nlon of the non-equiangular Driscoll-Healy grid that corresponds to the maximum harmonic degree nmax.

Parameters:

nmax (integer) – Maximum harmonic degree of the Driscoll-Healy grid

Returns:

• nlat (integer) – Number of latitudes

• nlon (integer) – Number of longitudes

property lat

Spherical latitudes.

property lon

Spherical longitudes.

property npoint

Total number of points.

property owner

Refer to pyharm.shc.Shc for documentation.

property r

Spherical radii.

class pyharm.crd.PointGridDH2(nmax, r=np.float64(1.0))

Class for equiangular Driscoll–Healy point grids.

For details, refer to charm_crd.

Create a PointGridDH2 class instance like this:

>>> import pyharm as ph
>>> gl = ph.crd.PointGridDH2(10)

Parameters:

• nmax (integer) – Maximum harmonic degree associated with the quadrature grid

• r (floating point) – Spherical radius of grid meridians, optional. Default value is 1.0.

Note

Once a PointGridDH2 class instance is created, neither its attributes nor its array elements are writeable.

property w

Integration weights on the unit sphere.

property nmax

Maximum harmonic degree associated with the quadrature grid points.

static shape(nmax)

Returns the number of latitudes nlat and the number of longitudes nlon of the equiangular Driscoll-Healy grid that corresponds to the maximum harmonic degree nmax.

Parameters:

nmax (integer) – Maximum harmonic degree of the Driscoll-Healy grid

Returns:

• nlat (integer) – Number of latitudes

• nlon (integer) – Number of longitudes

property lat

Spherical latitudes.

property lon

Spherical longitudes.

property npoint

Total number of points.

property owner

Refer to pyharm.shc.Shc for documentation.

property r

Spherical radii.

class pyharm.crd.CellSctr(ncell, data)

Class for scattered cells.

For details, refer to charm_crd.

To create a CellSctr class instance, always use one of the following factory methods:

• from_garbage(),

• from_zeros(),

• from_arrays().

Examples

• Create an instance with 5 scattered cells and all array elements initialized to zero:

  >>> import pyharm as ph
  >>> grd = ph.crd.CellSctr.from_zeros(5)
  

• Create an instance with 3 scattered cells with latitudes, longitudes and spherical radii taken from numpy arrays:

  >>> import numpy as np
  >>> import pyharm as ph
  >>> latmin = np.array([0.1, 0.2, 0.3])
  >>> latmax = latmin + 0.1
  >>> lonmin = np.array([0.5, 0.6, 0.7])
  >>> lonmax = lonmin + 0.1
  >>> r      = np.array([1.1, 1.2, 1.3])
  >>> sctr   = ph.crd.CellSctr.from_arrays(latmin, latmax,
  >>>                                      lonmin, lonmax, r)
  

Parameters:

• nlat (integer) – Number of grid latitudes

• nlon (integer) – Number of grid longitudes

• data (None, 0 or tuple) –

  Determines the way of initializing array elements:

  • None to not initialize array elements (malloc in C),

  • 0 to set all array elements to zero (calloc in C),

  • (latmin, latmax, lonmin, lonmax, r) to define the object’s minimum and maximum cell latitudes, minimum and maximum cell longitudes and spherical radii, respectively. The latmin, latmax, lonmin, lonmax and r variables must be numpy floating point arrays of dimension 1. All arrays must share the same number of elements.

Note

Once a CellSctr class instance is created, its attributes are not writeable, but all array elements are writeable.

classmethod from_garbage(ncell)

Returns a CellSctr class instance with uninitialized array elements (malloc in C).

Parameters:

ncell (integer) – Number of scattered cells

Returns:

out – CellSctr class instance

Return type:

CellSctr

classmethod from_zeros(ncell)

Returns a CellSctr class instance with all array elements initialized to zero (calloc in C).

Parameters:

ncell (integer) – Number of scattered cells

Returns:

out – CellSctr class instance

Return type:

CellSctr

classmethod from_arrays(latmin, latmax, lonmin, lonmax, r)

Returns a CellSctr class instance with minimum and maximum spherical cell latitudes, minimum and maximum cell longitudes and spherical radii taken from latmin, latmax, lonmin, lonmax and r, respectively.

Parameters:

• latmin (numpy array of floating points) – Minimum spherical cell latitudes

• latmax (numpy array of floating points) – Maximum spherical cell latitudes

• lonmin (numpy array of floating points) – Minimum spherical cell longitudes

• lonmax (numpy array of floating points) – Maximum spherical cell longitudes

• r (numpy array of floating points) – Spherical radii

Returns:

out – CellSctr class instance

Return type:

CellSctr

property latmax

Maximum spherical cell latitudes.

property latmin

Minimum spherical cell latitudes.

property lonmax

Maximum spherical cell longitudes.

property lonmin

Minimum spherical cell longitudes.

property ncell

Total number of cells.

property owner

Refer to pyharm.shc.Shc for documentation.

property r

Spherical radii (constant over each cell).

class pyharm.crd.CellGrid(nlat, nlon, data)

Class for custom cell grids.

For details, refer to charm_crd.

To create a CellGrid class instance, always use one of the following factory methods:

• from_garbage(),

• from_zeros(),

• from_arrays().

Examples

• Create an instance with 5 grid latitudes and 10 grid longitudes and initialize all array elements to zero:

  >>> import pyharm as ph
  >>> grd = ph.crd.CellGrid.from_zeros(5, 10)
  

• Create an instance with grid latitudes, longitudes and spherical radii taken from numpy arrays:

  >>> import numpy as np
  >>> import pyharm as ph
  >>> latmin = np.array([0.1, 0.2, 0.3])
  >>> latmax = latmin + 0.1
  >>> lonmin = np.array([0.5, 0.6, 0.7, 0.8, 0.9])
  >>> lonmax = lonmin + 0.1
  >>> r      = np.array([1.1, 1.2, 1.3])
  >>> grd    = ph.crd.CellGrid.from_arrays(latmin, latmax,
  >>>                                      lonmin, lonmax, r)
  

Parameters:

• nlat (integer) – Number of grid latitudes

• nlon (integer) – Number of grid longitudes

• data (None, 0 or tuple) –

  Determines the way of initializing array elements:

  • None to not initialize array elements (malloc in C),

  • 0 to set all array elements to zero (calloc in C),

  • (latmin, latmax, lonmin, lonmax, r) to define the object’s minimum and maximum cell latitudes, minimum and maximum cell longitudes and spherical radii, respectively. The latmin, latmax, lonmin, lonmax and r variables must be numpy floating point arrays of dimension 1. The latmin, latmax and r arrays must have the same number of elements, the same is true for lonmin and lonmax.

Note

Once a CellGrid class instance is created, its attributes are not writeable, but all array elements are writeable.

property latmax

Maximum spherical cell latitudes.

property latmin

Minimum spherical cell latitudes.

property lonmax

Maximum spherical cell longitudes.

property lonmin

Minimum spherical cell longitudes.

property ncell

Total number of cells.

property owner

Refer to pyharm.shc.Shc for documentation.

property r

Spherical radii (constant over each cell).

classmethod from_garbage(nlat, nlon)

Returns a CellGrid class instance with uninitialized array elements (malloc in C).

Parameters:

• nlat (integer) – Number of grid latitudes

• nlon (integer) – Number of grid longitudes

Returns:

out – CellGrid class instance

Return type:

CellGrid

classmethod from_zeros(nlat, nlon)

Returns a CellGrid class instance with all array elements initialized to zero (calloc in C).

Parameters:

• nlat (integer) – Number of grid latitudes

• nlon (integer) – Number of grid longitudes

Returns:

out – CellGrid class instance

Return type:

CellGrid

classmethod from_arrays(latmin, latmax, lonmin, lonmax, r)

Returns a CellGrid class instance with minimum and maximum spherical cell latitudes, minimum and maximum cell longitudes and spherical radii taken from latmin, latmax, lonmin, lonmax and r, respectively.

Parameters:

• latmin (numpy array of floating points) – Minimum spherical cell latitudes

• latmax (numpy array of floating points) – Maximum spherical cell latitudes

• lonmin (numpy array of floating points) – Minimum spherical cell longitudes

• lonmax (numpy array of floating points) – Maximum spherical cell longitudes

• r (numpy array of floating points) – Spherical radii

Returns:

out – CellGrid class instance

Return type:

CellGrid