author | jacint |
Fri, 07 May 2004 10:34:36 +0000 | |
changeset 575 | bdf7fb750e0e |
parent 289 | 98adf9276de0 |
child 685 | c7e37b066033 |
permissions | -rw-r--r-- |
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/*! |
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|
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\page maps How to write your own maps |
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|
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\section read-maps Readable Maps |
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|
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The readable maps are very frequently used as the input of the |
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algorithms. For this purpose the most straightforward is to use the |
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maps provided by Hugo's graph structres. Very often however, it is more |
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convenient and/or more efficient to write your own readable map. |
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You can find some example below. |
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This simple map assigns \f$\pi\f$ to each edge. |
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|
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\code |
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struct MyMap |
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{ |
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typedef double ValueType; |
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double operator[](Graph::Edge e) const { return M_PI;} |
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}; |
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\endcode |
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|
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An alternative way to define maps. For this, \c MapBase seems to |
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be a better name then \c NullMap |
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|
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\code |
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struct MyMap : public MapBase<Edge,double> |
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{ |
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double operator[](Graph::Edge e) const { return M_PI;} |
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}; |
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\endcode |
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|
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Or, if we had \c KeyType and \c ValueType |
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|
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\code |
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struct MyMap : public MapBase<Edge,double> |
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{ |
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ValueType operator[](KeyType e) const { return M_PI;} |
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}; |
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\endcode |
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|
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Here is a more complex example. It provides a length function which is obtained |
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from a base length function modified by a potential difference. |
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|
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\code |
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class MyLengthMap |
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{ |
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const Graph::EdgeMap &ol; |
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const Graph::NodeMap &pot; |
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|
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public: |
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typedef double ValueType; |
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|
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double operator[](Graph::Edge e) const { |
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return ol.get(e)-pot.get(v)-pot.get(u); |
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} |
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|
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MyComplexMap(const Graph::EdgeMap &o,const Graph::NodeMap &p) : |
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ol(o), pot(p); |
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}; |
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\endcode |
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|
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\todo Please improve on the english. |
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\todo Don't we need \e to \e require a 'typedef xxx KeyType' tag, as well? |
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*/ |