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hypergeo (version 1.2-13)

is.nonpos: Various utilities

Description

Various utilities needing nonce functions

Usage

is.near_integer(i, tol=getOption("tolerance")) is.nonpos(i) is.zero(i) isgood(x, tol) thingfun(z, complex=FALSE) crit(...) lpham(x,n)

Arguments

i
Numerical vector of suspected integers
tol
Tolerance
x
Argument to isgood() and lpham()
z
Complex vector
complex
In function thingfun(), Boolean with default FALSE meaning to return the modulus of the transforms and TRUE meaning to return the complex values themselves
n
second argument to lpham()
...
Ignored

Details

  • Function is.near_integer(i) returns TRUE if i is “near” [that is, within tol] an integer; if the option is unset then 1e-11 is used.
  • Function is.nonpos() returns TRUE if i is near a nonpositive integer
  • Function is.zero() returns TRUE if i is, er, near zero
  • Function isgood() checks for all elements of x having absolute values less than tol
  • Function thingfun() transforms input vector z by each of the six members of the anharmonic group, viewed as a subgroup of the Mobius group of functions. It returns a real six-column matrix with columns being the modulus of $z,z/(z-1),1-z,1/z,1/(1-z),1-1/z$. These six columns correspond to the primary argument in equations 15.3.3 to 15.3.9, p551 of AMS-55
  • Function crit() returns the two critical points, $1/2 +/- sqrt(3)i/2$. These points have unit modulus as do their six transforms by thingfun()
  • Function lpham() returns the log of the Pochhammer function $log(Gamma(x+n)/Gamma(x))$

Examples

Run this code

is.near_integer(-3)

is.zero(4)

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