Description of givens

givens_rotation<T>		Programmers Guide
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Category:functors

Component type:type

Description

Input a and b to the constructor to create a givens plane rotation object. Then apply the rotation to two vectors. There is a specialization of the givens rotation for complex numbers.

 [  c  s ] [ a ] = [ r ]
 [ -s  c ] [ b ]   [ 0 ]

Example

In apply_givens.cc:

  const int N = 5;
  double dx[] = { 1, 2, 3, 4, 5 };
  double dy[] = { 2, 4, 8, 16, 32};

  Vec x(dx, N), y(dy, N);
  double a = x[N-1];
  double b = y[N-1];

  givens_rotation<double> rot(a, b);

  rot.apply(x, y);

Definition

mtl.h

Template Parameters

Model of

Type requirements

the addition operator must be defined for T
the multiplication operator must be defined for T
the division operator must be defined for T
the abs() function must be defined for T

Members

Member	Where defined	Description
`givens_rotation ()`		Default constructor
`givens_rotation (T a_in, T b_in)`		Givens Plane Rotation Constructor
`void set_cs (T cin, T sin)`
`void scalar_apply (T& x, T& y)`		Apply plane rotation to two real scalars. (name change a VC workaround)
`template <class VecX, class VecY> void apply (VecX& x, VecY& y)`		Apply plane rotation to two vectors.
`T b ()`
`T s ()`

New members

Notes

See also