Last modified: December 2018

URL: http://cxc.harvard.edu/sherpa/ahelp/normgauss1d.html
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AHELP for CIAO 4.11 Sherpa v1

normgauss1d

Context: models

Synopsis

One-dimensional normalised gaussian function.

Syntax

normgauss1d

Example

>>> create_model_component("normgauss1d", "mdl")
>>> print(mdl)

Create a component of the normgauss1d model and display its default parameters. The output is:

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.fwhm     thawed           10  1.17549e-38  3.40282e+38           
   mdl.pos      thawed            0 -3.40282e+38  3.40282e+38           
   mdl.ampl     thawed            1 -3.40282e+38  3.40282e+38           

ATTRIBUTES

The attributes for this object are:

fwhm

The Full-Width Half Maximum of the gaussian. It is related to the sigma value by: FWHM = sqrt(8 * log(2)) * sigma.

pos

The center of the gaussian.

ampl

The amplitude refers to the integral of the model over the range -infinity to infinity.

Notes

The functional form of the model for points is:

f(x) = ampl * exp(-4 * log(2) * (x - pos)^2 / fwhm^2)
       ----------------------------------------------
               sqrt(pi / (4 * log(2))) * fwhm

and for an integrated grid it is the integral of this over the bin.


Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

models
gauss1d, normgauss2d