Adds Arg(X) sugar function (closes #625)

Author: coatless

ChangeLog

@@ -1,3 +1,9 @@
+2017-01-07  James J Balamuta  <[email protected]>
+
+        * inst/include/Rcpp/sugar/functions/complex.h: Added Arg() function
+        * inst/unitTests/runit.sugar.R: Added Arg() unit test to complex list
+        * inst/unitTests/cpp/sugar.cpp: Idem
+
 2017-01-06  Dirk Eddelbuettel  <[email protected]>
 
         * DESCRIPTION (Version, Date): Mark new minor version

inst/NEWS.Rd

@@ -18,6 +18,8 @@
     \itemize{
       \item Added new Sugar function \code{sample()} (Nathan Russell in 
       \ghpr{610}).
+      \item Added new Sugar function \code{Arg()} (James Balamuta in 
+      \ghpr{626} addressing \ghit{625}).
     }
     \item Changes in Rcpp unit tests
     \itemize{

inst/include/Rcpp/sugar/functions/complex.h

@@ -68,6 +68,7 @@ inline double complex__Re( Rcomplex x){ return x.r ; }
 		y.i = -x.i ;
 		return y ;
 	}
+    inline double complex__Arg( Rcomplex x ){ return ::atan2(x.i, x.r); }
 	// TODO: this does not use HAVE_C99_COMPLEX as in R, perhaps it should
 	inline Rcomplex complex__exp( Rcomplex x){
 		Rcomplex y ;
@@ -249,6 +250,7 @@ inline Rcomplex complex__tanh(Rcomplex z)
 RCPP_SUGAR_COMPLEX( Re, double )
 RCPP_SUGAR_COMPLEX( Im, double )
 RCPP_SUGAR_COMPLEX( Mod, double )
+RCPP_SUGAR_COMPLEX( Arg, double )
 RCPP_SUGAR_COMPLEX( Conj, Rcomplex )
 RCPP_SUGAR_COMPLEX( exp, Rcomplex )
 RCPP_SUGAR_COMPLEX( log, Rcomplex )

inst/unitTests/cpp/sugar.cpp

@@ -402,6 +402,7 @@ List runit_complex( ComplexVector cx ){
     	_["Im"]    = Im( cx ),
     	_["Conj"]  = Conj( cx ),
     	_["Mod"]   = Mod( cx ),
+    	_["Arg"]   = Arg( cx ),
     	_["exp"]   = exp( cx ),
     	_["log"]   = log( cx ),
     	_["sqrt"]  = sqrt( cx ),

inst/unitTests/runit.sugar.R

@@ -441,6 +441,7 @@ if (.runThisTest) {
                          Im    = Im(x),
                          Conj  = Conj(x),
                          Mod   = Mod(x),
+                         Arg   = Arg(x),
                          exp   = exp(x),
                          log   = log(x),
                          sqrt  = sqrt(x),