KKGCorrelation: Scalar-scalar-shear correlations

class treecorr.KKGCorrelation(config=None, *, logger=None, **kwargs)[source]

Bases: Corr3

This class handles the calculation and storage of a 3-point scalar-scalar-shear correlation function.

See the doc string of Corr3 for a description of how the triangles are binned.

With this class, point 3 of the triangle (i.e. the vertex opposite d3) is the one with the shear value. Use KGKCorrelation and GKKCorrelation for classes with the shear in the other two positions.

See the doc string of Corr3 for a description of how the triangles are binned along with the attributes related to the different binning options.

In addition to the attributes common to all Corr3 subclasses, objects of this class hold the following attributes:

Attributes:
  • zeta – The correlation function, \(\zeta\).

  • varzeta – The variance estimate, only including the shot noise propagated into the final correlation.

The typical usage pattern is as follows:

>>> kkg = treecorr.KKGCorrelation(config)
>>> kkg.process(cat1, cat2)       # Compute cross-correlation of two fields.
>>> kkg.process(cat1, cat2, cat3) # Compute cross-correlation of three fields.
>>> kkg.write(file_name)          # Write out to a file.
>>> zeta = kkg.zeta               # Access correlation function.
>>> zetar = kkg.zetar             # Or access real and imag parts separately.
>>> zetai = kkg.zetai
Parameters:
  • config (dict) – A configuration dict that can be used to pass in kwargs if desired. This dict is allowed to have addition entries besides those listed in Corr3, which are ignored here. (default: None)

  • logger – If desired, a logger object for logging. (default: None, in which case one will be built according to the config dict’s verbose level.)

Keyword Arguments:

**kwargs – See the documentation for Corr3 for the list of allowed keyword arguments, which may be passed either directly or in the config dict.

__init__(config=None, *, logger=None, **kwargs)[source]
finalize(vark1, vark2, varg)[source]

Finalize the calculation of the correlation function.

Parameters:
  • vark1 (float) – The variance of the first scalar field.

  • vark2 (float) – The variance of the second scalar field.

  • varg (float) – The variance per component of the shear field.

write(file_name, *, file_type=None, precision=None, write_patch_results=False, write_cov=False)[source]

Write the correlation function to the file, file_name.

For bin_type = LogRUV, the output file will include the following columns:

Column

Description

r_nom

The nominal center of the bin in r = d2 where d1 > d2 > d3

u_nom

The nominal center of the bin in u = d3/d2

v_nom

The nominal center of the bin in v = +-(d1-d2)/d3

meanu

The mean value \(\langle u\rangle\) of triangles that fell into each bin

meanv

The mean value \(\langle v\rangle\) of triangles that fell into each bin

For bin_type = LogSAS, the output file will include the following columns:

Column

Description

d2_nom

The nominal center of the bin in d2

d3_nom

The nominal center of the bin in d3

phi_nom

The nominal center of the bin in phi, the opening angle between d2 and d3 in the counter-clockwise direction

meanphi

The mean value \(\langle phi\rangle\) of triangles that fell into each bin

For bin_type = LogMultipole, the output file will include the following columns:

Column

Description

d2_nom

The nominal center of the bin in d2

d3_nom

The nominal center of the bin in d3

n

The multipole index n

In addition, all bin types include the following columns:

Column

Description

meand1

The mean value \(\langle d1\rangle\) of triangles that fell into each bin

meanlogd1

The mean value \(\langle \log(d1)\rangle\) of triangles that fell into each bin

meand2

The mean value \(\langle d2\rangle\) of triangles that fell into each bin

meanlogd2

The mean value \(\langle \log(d2)\rangle\) of triangles that fell into each bin

meand3

The mean value \(\langle d3\rangle\) of triangles that fell into each bin

meanlogd3

The mean value \(\langle \log(d3)\rangle\) of triangles that fell into each bin

zetar

The real part of the estimator of \(\zeta\)

zetai

The imag part of the estimator of \(\zeta\)

sigma_zeta

The sqrt of the variance estimate of \(\zeta\)

weight

The total weight of triangles contributing to each bin. (For LogMultipole, this is split into real and imaginary parts, weightr and weighti.)

ntri

The number of triangles contributing to each bin

If sep_units was given at construction, then the distances will all be in these units. Otherwise, they will be in either the same units as x,y,z (for flat or 3d coordinates) or radians (for spherical coordinates).

Parameters:
  • file_name (str) – The name of the file to write to.

  • file_type (str) – The type of file to write (‘ASCII’ or ‘FITS’). (default: determine the type automatically from the extension of file_name.)

  • precision (int) – For ASCII output catalogs, the desired precision. (default: 4; this value can also be given in the constructor in the config dict.)

  • write_patch_results (bool) – Whether to write the patch-based results as well. (default: False)

  • write_cov (bool) – Whether to write the covariance matrix as well. (default: False)

KGKCorrelation: Scalar-shear-scalar correlations

class treecorr.KGKCorrelation(config=None, *, logger=None, **kwargs)[source]

Bases: Corr3

This class handles the calculation and storage of a 3-point scalar-shear-scalar correlation function.

See the doc string of Corr3 for a description of how the triangles are binned.

With this class, point 2 of the triangle (i.e. the vertex opposite d2) is the one with the shear value. Use KKGCorrelation and GKKCorrelation for classes with the shear in the other two positions.

See the doc string of Corr3 for a description of how the triangles are binned along with the attributes related to the different binning options.

In addition to the attributes common to all Corr3 subclasses, objects of this class hold the following attributes:

Attributes:
  • zeta – The correlation function, \(\zeta\).

  • varzeta – The variance estimate, only including the shot noise propagated into the final correlation.

The typical usage pattern is as follows:

>>> kgk = treecorr.KGKCorrelation(config)
>>> kgk.process(cat1, cat2, cat1) # Compute cross-correlation of two fields.
>>> kgk.process(cat1, cat2, cat3) # Compute cross-correlation of three fields.
>>> kgk.write(file_name)          # Write out to a file.
>>> zeta = kgk.zeta               # Access correlation function.
>>> zetar = kgk.zetar             # Or access real and imag parts separately.
>>> zetai = kgk.zetai
Parameters:
  • config (dict) – A configuration dict that can be used to pass in kwargs if desired. This dict is allowed to have addition entries besides those listed in Corr3, which are ignored here. (default: None)

  • logger – If desired, a logger object for logging. (default: None, in which case one will be built according to the config dict’s verbose level.)

Keyword Arguments:

**kwargs – See the documentation for Corr3 for the list of allowed keyword arguments, which may be passed either directly or in the config dict.

__init__(config=None, *, logger=None, **kwargs)[source]
finalize(vark1, varg, vark2)[source]

Finalize the calculation of the correlation function.

Parameters:
  • vark1 (float) – The variance of the first scalar field.

  • varg (float) – The variance per component of the shear field.

  • vark2 (float) – The variance of the second scalar field.

write(file_name, *, file_type=None, precision=None, write_patch_results=False, write_cov=False)[source]

Write the correlation function to the file, file_name.

For bin_type = LogRUV, the output file will include the following columns:

Column

Description

r_nom

The nominal center of the bin in r = d2 where d1 > d2 > d3

u_nom

The nominal center of the bin in u = d3/d2

v_nom

The nominal center of the bin in v = +-(d1-d2)/d3

meanu

The mean value \(\langle u\rangle\) of triangles that fell into each bin

meanv

The mean value \(\langle v\rangle\) of triangles that fell into each bin

For bin_type = LogSAS, the output file will include the following columns:

Column

Description

d2_nom

The nominal center of the bin in d2

d3_nom

The nominal center of the bin in d3

phi_nom

The nominal center of the bin in phi, the opening angle between d2 and d3 in the counter-clockwise direction

meanphi

The mean value \(\langle phi\rangle\) of triangles that fell into each bin

For bin_type = LogMultipole, the output file will include the following columns:

Column

Description

d2_nom

The nominal center of the bin in d2

d3_nom

The nominal center of the bin in d3

n

The multipole index n

In addition, all bin types include the following columns:

Column

Description

meand1

The mean value \(\langle d1\rangle\) of triangles that fell into each bin

meanlogd1

The mean value \(\langle \log(d1)\rangle\) of triangles that fell into each bin

meand2

The mean value \(\langle d2\rangle\) of triangles that fell into each bin

meanlogd2

The mean value \(\langle \log(d2)\rangle\) of triangles that fell into each bin

meand3

The mean value \(\langle d3\rangle\) of triangles that fell into each bin

meanlogd3

The mean value \(\langle \log(d3)\rangle\) of triangles that fell into each bin

zetar

The real part of the estimator of \(\zeta\)

zetai

The imag part of the estimator of \(\zeta\)

sigma_zeta

The sqrt of the variance estimate of \(\zeta\)

weight

The total weight of triangles contributing to each bin. (For LogMultipole, this is split into real and imaginary parts, weightr and weighti.)

ntri

The number of triangles contributing to each bin

If sep_units was given at construction, then the distances will all be in these units. Otherwise, they will be in either the same units as x,y,z (for flat or 3d coordinates) or radians (for spherical coordinates).

Parameters:
  • file_name (str) – The name of the file to write to.

  • file_type (str) – The type of file to write (‘ASCII’ or ‘FITS’). (default: determine the type automatically from the extension of file_name.)

  • precision (int) – For ASCII output catalogs, the desired precision. (default: 4; this value can also be given in the constructor in the config dict.)

  • write_patch_results (bool) – Whether to write the patch-based results as well. (default: False)

  • write_cov (bool) – Whether to write the covariance matrix as well. (default: False)

GKKCorrelation: Shear-scalar-scalar correlations

class treecorr.GKKCorrelation(config=None, *, logger=None, **kwargs)[source]

Bases: Corr3

This class handles the calculation and storage of a 3-point shear-scalar-scalar correlation function.

See the doc string of Corr3 for a description of how the triangles are binned.

With this class, point 1 of the triangle (i.e. the vertex opposite d1) is the one with the shear value. Use KGKCorrelation and KKGCorrelation for classes with the shear in the other two positions.

See the doc string of Corr3 for a description of how the triangles are binned along with the attributes related to the different binning options.

In addition to the attributes common to all Corr3 subclasses, objects of this class hold the following attributes:

Attributes:
  • zeta – The correlation function, \(\zeta\).

  • varzeta – The variance estimate, only including the shot noise propagated into the final correlation.

The typical usage pattern is as follows:

>>> gkk = treecorr.GKKCorrelation(config)
>>> gkk.process(cat1, cat2)       # Compute cross-correlation of two fields.
>>> gkk.process(cat1, cat2, cat3) # Compute cross-correlation of three fields.
>>> gkk.write(file_name)          # Write out to a file.
>>> zeta = gkk.zeta               # Access correlation function.
>>> zetar = gkk.zetar             # Or access real and imag parts separately.
>>> zetai = gkk.zetai
Parameters:
  • config (dict) – A configuration dict that can be used to pass in kwargs if desired. This dict is allowed to have addition entries besides those listed in Corr3, which are ignored here. (default: None)

  • logger – If desired, a logger object for logging. (default: None, in which case one will be built according to the config dict’s verbose level.)

Keyword Arguments:

**kwargs – See the documentation for Corr3 for the list of allowed keyword arguments, which may be passed either directly or in the config dict.

__init__(config=None, *, logger=None, **kwargs)[source]
finalize(varg, vark1, vark2)[source]

Finalize the calculation of the correlation function.

Parameters:
  • varg (float) – The variance per component of the shear field.

  • vark1 (float) – The variance of the first scalar field.

  • vark2 (float) – The variance of the second scalar field.

write(file_name, *, file_type=None, precision=None, write_patch_results=False, write_cov=False)[source]

Write the correlation function to the file, file_name.

For bin_type = LogRUV, the output file will include the following columns:

Column

Description

r_nom

The nominal center of the bin in r = d2 where d1 > d2 > d3

u_nom

The nominal center of the bin in u = d3/d2

v_nom

The nominal center of the bin in v = +-(d1-d2)/d3

meanu

The mean value \(\langle u\rangle\) of triangles that fell into each bin

meanv

The mean value \(\langle v\rangle\) of triangles that fell into each bin

For bin_type = LogSAS, the output file will include the following columns:

Column

Description

d2_nom

The nominal center of the bin in d2

d3_nom

The nominal center of the bin in d3

phi_nom

The nominal center of the bin in phi, the opening angle between d2 and d3 in the counter-clockwise direction

meanphi

The mean value \(\langle phi\rangle\) of triangles that fell into each bin

For bin_type = LogMultipole, the output file will include the following columns:

Column

Description

d2_nom

The nominal center of the bin in d2

d3_nom

The nominal center of the bin in d3

n

The multipole index n

In addition, all bin types include the following columns:

Column

Description

meand1

The mean value \(\langle d1\rangle\) of triangles that fell into each bin

meanlogd1

The mean value \(\langle \log(d1)\rangle\) of triangles that fell into each bin

meand2

The mean value \(\langle d2\rangle\) of triangles that fell into each bin

meanlogd2

The mean value \(\langle \log(d2)\rangle\) of triangles that fell into each bin

meand3

The mean value \(\langle d3\rangle\) of triangles that fell into each bin

meanlogd3

The mean value \(\langle \log(d3)\rangle\) of triangles that fell into each bin

zetar

The real part of the estimator of \(\zeta\)

zetai

The imag part of the estimator of \(\zeta\)

sigma_zeta

The sqrt of the variance estimate of \(\zeta\)

weight

The total weight of triangles contributing to each bin. (For LogMultipole, this is split into real and imaginary parts, weightr and weighti.)

ntri

The number of triangles contributing to each bin

If sep_units was given at construction, then the distances will all be in these units. Otherwise, they will be in either the same units as x,y,z (for flat or 3d coordinates) or radians (for spherical coordinates).

Parameters:
  • file_name (str) – The name of the file to write to.

  • file_type (str) – The type of file to write (‘ASCII’ or ‘FITS’). (default: determine the type automatically from the extension of file_name.)

  • precision (int) – For ASCII output catalogs, the desired precision. (default: 4; this value can also be given in the constructor in the config dict.)

  • write_patch_results (bool) – Whether to write the patch-based results as well. (default: False)

  • write_cov (bool) – Whether to write the covariance matrix as well. (default: False)