Last modified: December 2018

URL: http://cxc.harvard.edu/sherpa/ahelp/delta1d.html
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AHELP for CIAO 4.11 Sherpa v1

delta1d

Context: models

Synopsis

One-dimensional delta function.

Syntax

delta1d

Description

The delta function model is only non-zero at a single point (or bin for integrated grids).


Example

>>> create_model_component("delta1d", "mdl")
>>> print(mdl)

Create a component of the delta1d model and display its default parameters. The output is:

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   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:

pos

The position of the signal.

ampl

The amplitude.

Notes

The functional form of the model for points is:

f(x) = ampl if x == pos
     = 0       otherwise

and for an integrated grid it is:

f(lo,hi) = ampl         if lo <= pos <= hi
         = 0            otherwise

This behavior is different to how the amplitude is handled in other models, such as Const1D .


Bugs

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

See Also

models
box1d, const1d, delta2d, stephi1d, steplo1d