igamma: Inverse of the digamma function

Description Usage Arguments Details Value Author(s) See Also Examples

Description

Function igamma is a numerical inverse of digamma.

Usage

1
igamma(v)

Arguments

v

a numeric in the range [-100000,18]

Details

igamma is vectorized; it is won by spline inversion of a grid; it works well for range [digamma(1e-5);digamma(1e8)] or [-100000,18].

Value

igamma(x) is a value u such that digamma(u is approximately x.

Author(s)

Peter Ruckdeschel [email protected]

See Also

digamma

Examples

1
igamma(digamma(c(1e-4,1,20,1e8)))

Example output

Loading required package: startupmsg
:startupmsg>  Utilities for Start-Up Messages (version 0.9.4)
:startupmsg> 
:startupmsg>  For more information see ?"startupmsg",
:startupmsg>  NEWS("startupmsg")

Loading required package: sfsmisc
Loading required package: SweaveListingUtils
:SweaveListingUtils>  Utilities for Sweave Together with
:SweaveListingUtils>  TeX 'listings' Package (version
:SweaveListingUtils>  0.7.7)
:SweaveListingUtils> 
:SweaveListingUtils>  NOTE: Support for this package
:SweaveListingUtils>  will stop soon.
:SweaveListingUtils> 
:SweaveListingUtils>  Package 'knitr' is providing the
:SweaveListingUtils>  same functionality in a better
:SweaveListingUtils>  way.
:SweaveListingUtils> 
:SweaveListingUtils>  Some functions from package 'base'
:SweaveListingUtils>  are intentionally masked ---see
:SweaveListingUtils>  SweaveListingMASK().
:SweaveListingUtils> 
:SweaveListingUtils>  Note that global options are
:SweaveListingUtils>  controlled by
:SweaveListingUtils>  SweaveListingoptions() ---c.f.
:SweaveListingUtils>  ?"SweaveListingoptions".
:SweaveListingUtils> 
:SweaveListingUtils>  For more information see
:SweaveListingUtils>  ?"SweaveListingUtils",
:SweaveListingUtils>  NEWS("SweaveListingUtils")
:SweaveListingUtils>  There is a vignette to this
:SweaveListingUtils>  package; try
:SweaveListingUtils>  vignette("ExampleSweaveListingUtils").


Attaching package: 'SweaveListingUtils'

The following objects are masked from 'package:base':

    library, require

:distr>  Object Oriented Implementation of Distributions (version
:distr>  2.6.2)
:distr> 
:distr>  Attention: Arithmetics on distribution objects are
:distr>  understood as operations on corresponding random variables
:distr>  (r.v.s); see distrARITH().
:distr> 
:distr>  Some functions from package 'stats' are intentionally masked
:distr>  ---see distrMASK().
:distr> 
:distr>  Note that global options are controlled by distroptions()
:distr>  ---c.f. ?"distroptions".
:distr> 
:distr>  For more information see ?"distr", NEWS("distr"), as well as
:distr>    http://distr.r-forge.r-project.org/
:distr>  Package "distrDoc" provides a vignette to this package as
:distr>  well as to several extension packages; try
:distr>  vignette("distr").


Attaching package: 'distr'

The following objects are masked from 'package:stats':

    df, qqplot, sd

[1] 1.000000e-04 1.000000e+00 2.099929e+01 1.734796e+09

distr documentation built on May 29, 2017, 10:12 p.m.