Changeset 1070:6aa1520a0f2f in lemon-0.x

Timestamp:

01/11/05 10:05:24 (20 years ago)

Author:

Alpar Juttner

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@1466

Message:

ShiftMap? and ScaleMap? added

Location:

src

Files:

• lemon/maps.h (modified) (2 diffs)
• test/maps_test.cc (modified) (1 diff)

src/lemon/maps.h

@@ -213 +213 @@
   }
 
+  ///Shift a maps with a constant.
+
+  ///This \ref concept::ReadMap "read only map" returns the sum of the
+  ///given map and a constant value.
+  ///Its \c Key and \c Value is inherited from \c M.
+  ///
+  ///Actually,
+  ///\code
+  ///  ShiftMap<X> sh(x,v);
+  ///\endcode
+  ///it is equivalent with
+  ///\code
+  ///  ConstMap<X::Key, X::Value> c_tmp(v);
+  ///  AddMap<X, ConstMap<X::Key, X::Value> > sh(x,v);
+  ///\endcode
+  template<class M> 
+  class ShiftMap
+  {
+    const M &m;
+    typename M::Value v;
+  public:
+    typedef typename M::Key Key;
+    typedef typename M::Value Value;
+
+    ///Constructor
+
+    ///Constructor
+    ///\param _m is the undelying map
+    ///\param _v is the shift value
+    ShiftMap(const M &_m,const Value &_v ) : m(_m), v(_v) {};
+    Value operator[](Key k) const {return m[k]+v;}
+  };
+  
+  ///Returns an \ref ShiftMap class
+
+  ///This function just returns an \ref ShiftMap class.
+  ///\relates ShiftMap
+  ///\todo A better name is required.
+  template<class M> 
+  inline ShiftMap<M> shiftMap(const M &m,const typename M::Value &v) 
+  {
+    return ShiftMap<M>(m,v);
+  }
+
   ///Difference of two maps
 
@@ -283 +327 @@
   }
  
+  ///Scale a maps with a constant.
+
+  ///This \ref concept::ReadMap "read only map" returns the value of the
+  ///given map multipied with a constant value.
+  ///Its \c Key and \c Value is inherited from \c M.
+  ///
+  ///Actually,
+  ///\code
+  ///  ScaleMap<X> sc(x,v);
+  ///\endcode
+  ///it is equivalent with
+  ///\code
+  ///  ConstMap<X::Key, X::Value> c_tmp(v);
+  ///  MulMap<X, ConstMap<X::Key, X::Value> > sc(x,v);
+  ///\endcode
+  template<class M> 
+  class ScaleMap
+  {
+    const M &m;
+    typename M::Value v;
+  public:
+    typedef typename M::Key Key;
+    typedef typename M::Value Value;
+
+    ///Constructor
+
+    ///Constructor
+    ///\param _m is the undelying map
+    ///\param _v is the scaling value
+    ScaleMap(const M &_m,const Value &_v ) : m(_m), v(_v) {};
+    Value operator[](Key k) const {return m[k]*v;}
+  };
+  
+  ///Returns an \ref ScaleMap class
+
+  ///This function just returns an \ref ScaleMap class.
+  ///\relates ScaleMap
+  ///\todo A better name is required.
+  template<class M> 
+  inline ScaleMap<M> scaleMap(const M &m,const typename M::Value &v) 
+  {
+    return ScaleMap<M>(m,v);
+  }
+
   ///Quotient of two maps
 

src/test/maps_test.cc

@@ -27 +27 @@
   checkConcept<ReadMap<A,double>, NegMap<DoubleMap> >();
   checkConcept<ReadMap<A,double>, AbsMap<DoubleMap> >();
+  checkConcept<ReadMap<A,double>, ShiftMap<DoubleMap> >();
+  checkConcept<ReadMap<A,double>, ScaleMap<DoubleMap> >();
   
   checkConcept<ReadMap<B,double>, ComposeMap<DoubleMap,ReadMap<B,A> > >();