Erfc

class sherpa.models.basic.Erfc(name='erfc')

Bases: sherpa.models.model.RegriddableModel1D

One-dimensional complementary error function.

The function is described at [1].

ampl

The amplitude of the model.

offset

The offset of the model.

sigma

The scaling factor.

See also

Erf

Notes

The functional form of the model for points is:

f(x) = ampl * erfc((x - offset) / sigma)

erfc(y) = (2 / sqrt(pi)) Int_y^infinity exp(-t^2) dt

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

References

[1]	http://mathworld.wolfram.com/Erfc.html

Attributes Summary

thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars

Methods Summary

apply(outer, *otherargs, **otherkwargs)
calc(pars, xlo, *args, **kwargs)
get_center()
guess(dep, *args, **kwargs)	Set an initial guess for the parameter values.
regrid(*arrays)
reset()
set_center(*args, **kwargs)
startup()	Called before a model may be evaluated multiple times.
teardown()	Called after a model may be evaluated multiple times.

Attributes Documentation

thawedparhardmaxes

thawedparhardmins

thawedparmaxes

thawedparmins

thawedpars

Methods Documentation

apply(outer, *otherargs, **otherkwargs)

calc(pars, xlo, *args, **kwargs)

get_center()

guess(dep, *args, **kwargs)

Set an initial guess for the parameter values.

Attempt to set the parameter values, and ranges, for the model to match the data values. This is intended as a rough guess, so it is expected that the model is only evaluated a small number of times, if at all.

regrid(*arrays)

reset()

set_center(*args, **kwargs)

startup()

Called before a model may be evaluated multiple times.

See also

teardown()

teardown()

Called after a model may be evaluated multiple times.

See also

setup()