.. highlightlang:: us

.. index:: histc

.. _histc:

histc
=====

.. us.tag  histc NOTREADYENGLISH New532  math-base

:ref:`histc` calculates a histogram.

.. function::  r = histc(v, edges)

.. us.return

**Return Value**

*r* is a vector of length ``len(e)-1``. Each element contains the number of 
points that fall between the elements in the edges vector (v[i] >= edges[j] and
v[i] < edges[j+1]). The last bin counts any values of v that match edges(end). 
Values outside the values in edges are not counted. In case of an error the
function returns -1.

.. us.params

**Parameters**

.. uparam:: v

   *v* is a real vector or matrix.

.. uparam:: edges

   *edges* is a vector with bin edges. The vector must have at least two elements.
   The elements must be sorted monotone increasing (edges[i] < edges[i+1]).

.. us.example

**Example**

:: 

   * a = [1, 1.2, 1.41, 1.65, 1.66, 1.71, 1.8, 2.0]
   * edges = [1, 1.2, 1.4, 1.6, 1.8, 2.0]
   * histc(a, edges)
   1
   1
   1
   3
   2

Histogram of a bitmap:

::

   hImg = ImageCreate("c:/test.png");
   b = ImageUpdate(hImg);
   if (b == FALSE) error("image not found");
   g = ImageGetPixelGray(hImg);
   r = histc(g, 0:255);
   plot(r);

.. us.history

**History**

.. list-table::
   :header-rows: 1

   * - Version
     - Description
   * - 5.3.2
     - New.

.. seealso::
   :ref:`overview-mathematic`,
   :ref:`cumsum`,
   :ref:`histogram`

:sub:`id-926486`