# source


This section describes how Lenstool simulate sources.



## grid int

If `int = 1`, the sources are placed on a regular grid of size `n_source`$\times$`n_source` in the source plane corresponding to the field in the image plane described in section [`champ`](). If the [`polaire`]() is set, then sources are placed on a polar grid. If `int = 0`, then sources are placed randomly in the rectangular field corresponding to the source plane of the field described in section [champ]().

## random int

This force the seed value for the random number generator, better if negative. By default, Lenstool uses a random seed based on the local time on the machine.

## n\_source int

Number of sources to draw.

## elip\_max float

Maximum ellipticity of the drawing sources. The ellipticity of the sources is drawn from 0 to `float` with a uniform law.

## dist\_z int float1 float2

Specify how Lenstool draw the redshift of the sources.

If `int = 0`, all the redshift will be set to the value specified by the keyword [z_source]().
If `int = 1`, the redshifts will be drawn with a uniform law between redshifts `float1` and `float2`.
If `int = 2` and the [`smail`]() keyword is set, the redshifts will be drawn with a [Smail et al.]() distribution.

## z\_source float 

Redshift of the sources without redshift in Lenstool. Default value: $z = 0.8$.

## taille float

Set the size of the source in arcsecond.

## smail float1 float2 float3

Specify the shape of a [Smail et al.]() distribution, from which redshifts are randomly drawn.