Polynom1D

class sherpa.models.basic.Polynom1D(name='polynom1d')

Bases: sherpa.models.model.ArithmeticModel

One-dimensional polynomial function of order 8.

The maximum order of the polynomial is 8. The default setting has all parameters frozen except for c0, which means that the model acts as a constant.

c0

The constant term.

c1

The amplitude of the (x-offset) term.

c2

The amplitude of the (x-offset)^2 term.

c3

The amplitude of the (x-offset)^3 term.

c4

The amplitude of the (x-offset)^4 term.

c5

The amplitude of the (x-offset)^5 term.

c6

The amplitude of the (x-offset)^6 term.

c7

The amplitude of the (x-offset)^7 term.

c8

The amplitude of the (x-offset)^8 term.

offset

There is a degeneracy between c0 and offset, so it is recommended that at least one of these remains frozen.

See also

PowLaw1D, Polynom2D

Notes

The functional form of the model for points is:

f(x) = sum_(i=0)^(i=8) c_i * (x - offset)^i

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

Attributes Summary

thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars

Methods Summary

apply(outer, \*otherargs, \*\*otherkwargs)
calc(pars, xlo, \*args, \*\*kwargs)
get_center()
guess(dep, \*args, \*\*kwargs)
reset()
set_center(\*args, \*\*kwargs)
startup()
teardown()

Attributes Documentation

thawedparhardmaxes

thawedparhardmins

thawedparmaxes

thawedparmins

thawedpars

Methods Documentation

apply(outer, *otherargs, **otherkwargs)

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

get_center()

guess(dep, *args, **kwargs)

reset()

set_center(*args, **kwargs)

startup()

teardown()