new feature powerspace

README.rst

@@ -1,15 +1,15 @@
 #############
 Binning Utils
 #############
-|TestStatus| |PyPiStatus| |BlackStyle|
+|TestStatus| |PyPiStatus| |BlackStyle| |BlackPackStyle| |MITLicenseBadge|
 
 A collection of tools to help with binning.
 
 *******
 power10
 *******
 
-Create binning with power-space which is aligned to decades.
+Create binning in geomspace which is aligned to decades.
 
 .. code:: python
 
@@ -24,11 +24,39 @@ Create binning with power-space which is aligned to decades.
     array([ 1., 2.15, 4.64, 10., 21.54, 46.41, 100.])
 
 
+**********
+powerspace
+**********
+
+To make bin edges for distributions occuring in power laws.
+For example to histogram the energies of cosmic rays which occur in a
+power law with slope ``-2.7``
+
+.. code:: python
+
+    import binning_utils
+    binning_utils.powerspace(
+        start=1,
+        stop=10,
+        power_slope=-2.7,
+        size=10,
+    )
+    array([ 1.        ,  1.07017144,  1.15544801,  1.26196439,  1.39995703,
+        1.58808152,  1.86493297,  2.32807878,  3.33799855, 10.        ])
+
+
+
 .. |BlackStyle| image:: https://img.shields.io/badge/code%20style-black-000000.svg
     :target: https://github.com/psf/black
 
+.. |BlackPackStyle| image:: https://img.shields.io/badge/pack%20style-black-000000.svg
+    :target: https://github.com/cherenkov-plenoscope/black_pack
+
 .. |TestStatus| image:: https://github.com/cherenkov-plenoscope/binning_utils/actions/workflows/test.yml/badge.svg?branch=main
     :target: https://github.com/cherenkov-plenoscope/binning_utils/actions/workflows/test.yml
 
+.. |MITLicenseBadge| image:: https://img.shields.io/badge/License-GPL%20v3-blue.svg
+    :target: https://opensource.org/licenses/MIT
+
 .. |PyPiStatus| image:: https://img.shields.io/pypi/v/binning_utils_sebastian-achim-mueller
     :target: https://pypi.org/project/binning_utils_sebastian-achim-mueller

binning_utils/__init__.py

@@ -1,6 +1,7 @@
 from .version import __version__
 from . import power10
 from . import sphere
+from .powerspace import powerspace
 import numpy as np
 
 

binning_utils/powerspace.py

@@ -0,0 +1,32 @@
+import numpy as np
+
+
+def powerspace(start, stop, power_slope, size):
+    """
+    Parameters
+    ----------
+    start : float
+        Lower limit of the space.
+    stop : float
+        Upper limit of the space.
+    power_slope : float
+        Slope of the power law.
+    size : int
+        The number of samples.
+
+    Returns
+    -------
+    x : array_like
+        Values between 'start' and 'stop' spaced to histogram a power law
+        with slope 'power_slope' in equal amounts in each bin.
+    """
+    # Adopted from CORSIKA
+    rd = np.linspace(0.0, 1.0, size)
+    if power_slope != -1.0:
+        ll = start ** (power_slope + 1.0)
+        ul = stop ** (power_slope + 1.0)
+        slex = 1.0 / (power_slope + 1.0)
+        return (rd * ul + (1.0 - rd) * ll) ** slex
+    else:
+        ll = stop / start
+        return start * ll**rd

binning_utils/version.py

@@ -1 +1 @@
-__version__ = "0.0.11"
+__version__ = "0.0.12"