Log function

Log functions

Log functions as per the Gnu Scientific Library, reference manual section 7.25 and AMS-55, chapter 4. These functions are declared in header file gsl_sf_log.h

gsl_sf_log(x, give=FALSE, strict=TRUE)
log_abs(x, give=FALSE, strict=TRUE)
complex_log(zr, zi=NULL, r.and.i=TRUE, give=FALSE, strict=TRUE)
log_1plusx(x, give=FALSE, strict=TRUE)
log_1plusx_mx(x, give=FALSE, strict=TRUE)

Arguments

• x: input: real values

• zr: In complex_log(), the real part of the argument

• zi: In complex_log(), the imaginary part of the argument. If missing (ie takes the default value of NULL), interpret zr as complex, even if real

• r.and.i: In complex_log(), Boolean variable with default value of TRUE meaning to return a complex variable as per the details section below; and FALSE meaning to return the values as advertised in the GSL manual

• give: Boolean with TRUE meaning to return a list of three items: the value, an estimate of the error, and a status number

• strict: Boolean, with TRUE meaning to return NaN

  if status is an error

References

https://www.gnu.org/software/gsl/

Author(s)

Robin K. S. Hankin

Examples

x <- seq(from=0.1,to=2,by=0.01)
log(x)   #table 7.5 of Ab and St