https://github.com/cran/fields
Tip revision: 66561c3c33070df2578182fed373cf04d4a7c1c6 authored by Douglas Nychka on 13 December 2016, 06:57:09 UTC
version 8.7
version 8.7
Tip revision: 66561c3
expfnC.c
/*
fields, Tools for spatial data
Copyright 2004-2007, Institute for Mathematics Applied Geosciences
University Corporation for Atmospheric Research
Licensed under the GPL -- www.gpl.org/licenses/gpl.html
*/
#include <R.h>
#include <Rinternals.h>
#include <R_ext/Arith.h>
#include <Rmath.h>
#include <float.h>
SEXP expfnC(SEXP n, SEXP d2, SEXP par) {
int In, i;
double Dpar, par2;
double *Pd2;
//caste R variables to C variables, allocate answer vector
In = INTEGER(n)[0];
Dpar = REAL(par)[0];
par2 = Dpar/2;
Pd2 = REAL(d2);
for(i = 0; i < In; i++) {
Pd2[i] = exp(-1*pow(Pd2[i], par2));
}
return(R_NilValue);
}