shear bias


Authors:  M. Kilbinger, A. Pujol
Language: Python
Download: GitHub
Description: shear_bias is a package that contains tools and scripts for shear bias estimation for weak gravitational lensing analysis.


Download the code from the github repository.

git clone

A directory shear_bias is created. There, call the setup script to install the package.

cd shear_bias
python install



Authors: M. Kilbinger
Language: C
Download: github/nicaea
Description: Numerical routines to calculate cosmology and weak-lensing quantities.

nicaea [ni'kaia]: NumerIcal Cosmology And lEnsing cAlculationsNice coat of arms

Martin Kilbinger, CEA Saclay, Service d'Astrophysique (SAp), France


nicaea is a C-code providing numerical routines to calculate cosmology and weak-lensing quantities and functions from theoretical models of the large-scale structure. nicaea is the base of the cosmology module of the CosmoPMC package.


Get the latest stable version by cloning the most recent version from github . A readme file (types .rst, .html, .pdf and other) is included in the package. Check also readthedocs for documentation. New features in version 2.7 (Feb 2017):

  • New lensing projection types: extended Limber, spherical-sky prefactor, second-order Limber, full projection (Kilbinger et al. 2017, arXiv:1702.05301)
  • Photometric redshift errors (so far supported Gaussian with second Gaussian for outliers)
  • Modification of halomodel: mass function now normalized to physical volume (new division by a^3)
  • Added CMB normalization A_s
  • Added options to lensingdemo

For older versions of nicaea please contact me (martin.kilbinger at Note that v2.6 was skipped, the previous released version is 2.5


There is no dedicated paper that describes nicaea. To reference nicaea, please use the following publication: arXiv:0810.5129, in which something that resembles the first version of nicaea has been used.


Martin Kilbinger
Karim Benabed (error propagation, code design)
Jean Coupon (HOD, halomodel)
Henry J. McCracken (HOD)
Liping Fu (decomp_eb)
François Lanusse (many enhancements and interface additions)

Please feel free to send questions, feedback and bug reports to If you want to be added to the nicaea mailing list, to get updates about new versions and bug-fixes, send me a mail to

CosmoPMC (cosmology sampling with Population Monte Carlo [PMC])
pmclib (Population Monte Carlo library)
camelus (Model for weak-lensing peak counts)
athena (tree code for second-order correlations)
reduced-shear corrections

Last updated April 2018.



Authors: M. Kilbinger
Language: C
Download: athena_1.7.tgz
Description: A tree code for calculating second-order correlation functions.

athena: Tree code for second-order correlation functions

athena olive tree Martin Kilbinger, CEA Saclay, Service d'Astrophysique (SAp), France

METHOD athena is a 2d-tree code written in C, which estimates second-order correlation functions from input galaxy catalogues. These include shear-shear correlations (cosmic shear), position-shear (galaxy-galaxy lensing) and position-position (spatial angular correlation).

  DOWNLOAD Get the latest version athena_1.7.tgz. A readme file is available. Run the code on the test data set. New features and bug fixes in version 1.7 (Mar 2014):

  • General
    • Added FITS file support. Input catalogues and output correlation function files can be both in ascii or fits format.
      (Note: If reading a FITS file causes a segmentation fault, remove the compiler option "-std=c99", either from CMakeLists.txt or src/Makefile.athena".)
    • Format of resample files changed, only relevant columns are output.
    • Compilation of code automated using cmake. Alternatively, the traditional Makefile is still usable.
    • Directory structure changed.

To compile and run the code, you need a C-compiler. To calculate the angular correlation function, including reading mask files and creating random catalogues, gsl and perl and required. The library cfitsio is optional (for FITS file support).

Further scripts are part of the athena package:

  • The python script calculates (band-)power spectrum by integrating over the correlation function using an estimator from this paper. Further, the aperture-mass dispersion is compuated, also via integrating the correlation function.
  • The perl script is the master script for angular correlation function calculations. It creates random catalogues and calls athena for all necessary combinations of data and random catalogues, including redshift bins, and outputs the Landy & Szalay (1993) and Hamilton (1993) estimators of the correlation function.
  • Two perl scripts ( and calculate projections of an input catalogue in spherical coordinates, and transform an arbitrary (ascii) input catalogue into an athena-readable format.
  • The python script runs a series of tests for easy comparison with expected results.
  • Various scripts to transform and plot resampled data (e.g. Jackknife)

  • For older versions of athena please contact me (martin.kilbinger at


Martin Kilbinger
Christopher Bonnett (gal-gal lensing)
Jean Coupon (venice)

With helpful suggestions from Henry McCracken, Lance Miller, and Barnaby Rowe. Ami Choi, Jonathan Benjamin, Matthieu Béthermin, and Shahab Joudaki are thanked for testing the code and bug-hunting.

Please feel free to send questions, feedback and bug reports to If you want to be added to the athena mailing list, to get updates about new versions and bug-fixes, send me a mail to

CosmoPMC (cosmology sampling with Population Monte Carlo [PMC])
nicaea (cosmology and lensing package)
reduced-shear corrections home

Last updated February 2017.



Authors: Chieh-An Lin
Language: C
Download: GitHub
Description: A code for fast weak lensing peak count modelling.

Counts of Amplified Mass Elevations from Lensing with Ultrafast Simulations
Chieh-An Lin (University of Edinburgh)



Camelus is a fast weak lensing peak count modeling in C. It provides a prediction on peak counts from input cosmological parameters.

Here is the summary of the algorithm:

  • Sample halos from a mass function
  • Assign density profiles, randomize their positions
  • Compute the projected mass, add noise
  • Make maps and create peak catalogues

For a more detailed description, please take a look at Lin & Kilbinger (2015a).


Please check the GitHub page of Camelus.


The following softwares are required:


Current release: Camelus v1.31

New features in v1.31 - Mar 22, 2016:

  • Made installation more friendly by removing the dependency on cfitsio and mpi
  • Added the routine for computing 1-halo & 2-halo terms of the convergence profile
  • Flexible parameter space for PMC ABC
  • Remove files: FITSFunctions.c/.h

New features in v1.3 - Dec 09, 2015:

  • New files: constraint.c/.h
  • Allowed multiscale peaks in one data vector
  • Allowed a data matrix from several realizations
  • Used the local galaxy density as the noise level in the S/N
  • Increased the parameter dimension for PMC ABC
  • Changed the summary statistic options for PMC ABC

New features in v1.2 - Apr 06, 2015:

  • Improved the computation speed by a factor of 6~7
  • Converted the halo array structure into a binned structure, called "halo_map"
  • Converted the galaxy tree structure into a binned structure, called "gal_map"
  • Added the population Monte Carlo approximate Monte Carlo (PMC ABC) algorithm

New features in v1.1 - Jan 19, 2015:

  • Fixed the bug from calculating halo radii

New features in v1.0 - Oct 24, 2014:

  • Fast weak lensing peak count modeling


Contact information


Please feel free to send questions, feedback and bug reports to calin AT roe DOT ac DOT uk.

Last updated Jun 26, 2015.