Add no_init for matrices (#159)

Author: kevinushey

ChangeLog

@@ -1,7 +1,15 @@
+2014-07-29  Kevin Ushey  <[email protected]>
+
+        * inst/include/Rcpp/vector/no_init.h: Add no_init for matrices
+        * inst/include/Rcpp/vector/Matrix.h: Idem
+        * inst/include/Rcpp/vector/Vector.h: Idem
+        * inst/unitTests/runit.Matrix.R: Idem
+        * inst/unitTests/cpp/Matrix.cpp: Idem
+
 2014-07-29  Dirk Eddelbuettel  <[email protected]>
 
         * inst/include/Rcpp/vector/proxy.h: Removed operator bool() cast as
-        discusses by Christian Authmann on rcpp-devel 
+        discusses by Christian Authmann on rcpp-devel
 
 2014-07-28  Dirk Eddelbuettel  <[email protected]>
 

inst/include/Rcpp/vector/Matrix.h

@@ -35,6 +35,7 @@ class Matrix : public Vector<RTYPE, StoragePolicy>, public MatrixBase<RTYPE, tru
     typedef MatrixColumn<RTYPE> Column ;
     typedef SubMatrix<RTYPE> Sub ;
 
+    typedef StoragePolicy<Matrix> Storage ;
     typedef Vector<RTYPE, StoragePolicy> VECTOR ;
     typedef typename VECTOR::iterator iterator ;
     typedef typename VECTOR::const_iterator const_iterator ;
@@ -84,6 +85,10 @@ class Matrix : public Vector<RTYPE, StoragePolicy>, public MatrixBase<RTYPE, tru
     }
     Matrix& operator=( const SubMatrix<RTYPE>& ) ;
 
+    explicit Matrix( const no_init_matrix& obj) {
+        Storage::set__( Rf_allocMatrix( RTYPE, obj.nrow(), obj.ncol() ) );
+    }
+
     inline int ncol() const {
         return VECTOR::dims()[1];
     }

inst/include/Rcpp/vector/Vector.h

@@ -79,7 +79,7 @@ class Vector :
         Storage::set__( r_cast<RTYPE>(proxy.get()) ) ;
     }
 
-    explicit Vector( const no_init& obj) {
+    explicit Vector( const no_init_vector& obj) {
         Storage::set__( Rf_allocVector( RTYPE, obj.get() ) ) ;
     }
 

inst/include/Rcpp/vector/no_init.h

@@ -24,9 +24,12 @@
 
 namespace Rcpp{
 
-class no_init {
+template <int RTYPE, template <class> class StoragePolicy>
+class Matrix;
+
+class no_init_vector {
 public:
-    no_init(int size_): size(size_){}
+    no_init_vector(int size_): size(size_){}
 
     inline int get() const {
         return size;
@@ -41,5 +44,36 @@ class no_init {
     int size ;
 } ;
 
+class no_init_matrix {
+public:
+    no_init_matrix(int nr_, int nc_): nr(nr_), nc(nc_) {}
+
+    inline int nrow() const {
+        return nr;
+    }
+
+    inline int ncol() const {
+        return nc;
+    }
+
+    template <int RTYPE, template <class> class StoragePolicy >
+    operator Matrix<RTYPE, StoragePolicy>() const {
+        return Rf_allocMatrix(RTYPE, nr, nc);
+    }
+
+private:
+    int nr;
+    int nc;
+} ;
+
+inline no_init_vector no_init(int size) {
+    return no_init_vector(size);
+}
+
+inline no_init_matrix no_init(int nr, int nc) {
+    return no_init_matrix(nr, nc);
+}
+
+
 }
 #endif

inst/unitTests/cpp/Matrix.cpp

@@ -216,3 +216,12 @@ void runit_rownames_colnames_proxy(
 void runit_rownames_proxy(NumericMatrix x) {
     rownames(x) = CharacterVector::create("A", "B", "C");
 }
+
+// [[Rcpp::export]]
+NumericMatrix runit_no_init_matrix() {
+    NumericMatrix x = no_init(2, 2);
+    for (int i = 0; i < 4; i++) {
+        x[i] = i;
+    }
+    return x;
+}

inst/unitTests/runit.Matrix.R

@@ -160,5 +160,10 @@ if (.runThisTest) {
         checkEquals(colnames(m), NULL)
     }
 
+    test.NumericMatrix.no.init <- function() {
+      m <- runit_no_init_matrix()
+      checkEquals(m, matrix(c(0, 1, 2, 3), nrow = 2))
+    }
+
 
 }