Version 5.0 The LEDA User Manual

eal matrix M + const real matrix& M1
real matrix M − const real matrix& M1
real matrix M ∗ const real matrix& M1
real vector M ∗ const real vector& vec
Addition.
Precondition: M.dim1() == M1.dim1() and M.dim2()
== M1.dim2().
Subtraction.
Precondition: M.dim1() == M1.dim1() and M.dim2()
== M1.dim2().
Multiplication.
Precondition: M.dim2() == M1.dim1().
Multiplication with vector.
Precondition: M.dim2() == vec.dim().
real matrix M ∗ real x Multiplication with real x.
void M.print(ostream& O)
void M.print( ) prints M cout.
prints M row by row to ostream O.
void M.read(istream& I) reads M.dim1( ) × M.dim2 ( ) numbers from input
stream I and writes them row by row into matrix M.
void M.read( ) prints M from cin.
ostream&
istream&
ostream& O ≪ const real matrix& M
istream& I ≫ real matrix& M
writes matrix M row by row to the output stream O.
reads a matrix row by row from the input stream I and
assigns it to M.
4. Implementation
Data type real matrix is implemented by two-dimensional arrays of real numbers. Operations
det, solve, and inv take time O(n 3 ) operations on reals, dim1, dim2, row, and col
take constant time, all other operations perform O(nm) operations on reals. The space
requirement is O(nm) plus the space for the nm entries of type real.