#include <R.h> 
#include <Rmath.h>
#include <Rdefines.h>

// in addition to the usuals:
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>

SEXP myfunction(SEXP a, SEXP b){
  a=PROTECT(a);
  b=PROTECT(b);
  
  // creating pointers to input arguments
  int * a_val = INTEGER(a);
  double * b_val = REAL(b);
	
	// accessing the input arguments:
	printf("a = %d and b[0] = %f\n", *a_val, b_val[0]);
	
	// allocating memory for the new array,with length *a:
	SEXP newobject1 = PROTECT(allocVector(REALSXP, (*a_val)));
	//creating C pointer to the new array:
	double * newarray = REAL(newobject1);
	
	// allocating memory for a double:
	SEXP newobject2 = PROTECT(allocVector(REALSXP, 1));
	//creating C pointer to the new double:
	double * newdouble = REAL(newobject2); 
	
	// the new array should contain the square roots of the array b_val
	int i=0;
	*newdouble=0.0;
	// the code:
	for(i=0;i<(*a_val);i++){
	  newarray[i] = sqrt(b_val[i]);
	  if(newarray[i]>*newdouble){
	    *newdouble = newarray[i];
	  }
	}
	
	
  // creating a list to hold the two return values. 
  SEXP ret = PROTECT(allocVector(VECSXP, 2)); //the list to be returned in R
	
	//inserting the desired objects into the list (or at least pointers to them):
  SET_VECTOR_ELT(ret, 0, newobject1);
  SET_VECTOR_ELT(ret, 1, newobject2);
  
  // creating list of names/titles to be returned in the output list
  SEXP names = PROTECT(allocVector(STRSXP, 2));
  SET_STRING_ELT(names, 0, mkChar("the_new_array"));
  SET_STRING_ELT(names, 1, mkChar("the_new_double"));
  setAttrib(ret, R_NamesSymbol, names);
  
  UNPROTECT(6);
  return ret;
}
SEXP myfunction_silent(SEXP a, SEXP b){
  a=PROTECT(a);
  b=PROTECT(b);
  
  // creating pointers to input arguments
  int * a_val = INTEGER(a);
  double * b_val = REAL(b);
	
	// accessing the input arguments:
	//printf("a = %d and b[0] = %f\n", *a_val, b_val[0]);
	
	// allocating memory for the new array,with length *a:
	SEXP newobject1 = PROTECT(allocVector(REALSXP, (*a_val)));
	//creating C pointer to the new array:
	double * newarray = REAL(newobject1);
	
	// allocating memory for a double:
	SEXP newobject2 = PROTECT(allocVector(REALSXP, 1));
	//creating C pointer to the new double:
	double * newdouble = REAL(newobject2); 
	
	// the new array should contain the square roots of the array b_val
	int i=0;
	*newdouble=0.0;
	// the code:
	for(i=0;i<(*a_val);i++){
	  newarray[i] = sqrt(b_val[i]);
	  if(newarray[i]>*newdouble){
	    *newdouble = newarray[i];
	  }
	}
	
	
  // creating a list to hold the two return values. 
  SEXP ret = PROTECT(allocVector(VECSXP, 2)); //the list to be returned in R
	
	//inserting the desired objects into the list (or at least pointers to them):
  SET_VECTOR_ELT(ret, 0, newobject1);
  SET_VECTOR_ELT(ret, 1, newobject2);
  
  // creating list of names/titles to be returned in the output list
  SEXP names = PROTECT(allocVector(STRSXP, 2));
  SET_STRING_ELT(names, 0, mkChar("the_new_array"));
  SET_STRING_ELT(names, 1, mkChar("the_new_double"));
  setAttrib(ret, R_NamesSymbol, names);
  
  UNPROTECT(6);
  return ret;
}