>

> restart;

> with( LinearAlgebra );

>

> infolevel[LinearAlgebra] := 2:

>

> A := HilbertMatrix( 5 );

> B := evalf( A );

>

> st := time():

> MatrixInverse( A );

> time()-st;

>

> st := time():

> MatrixInverse( B );

> time()-st;

MatrixInverse:   "calling external function"

MatrixInverse:   "NAG"   hw_f07adf

MatrixInverse:   "NAG"   hw_f07ajf

>

> UseHardwareFloats := false;

> Digits := 20;

> st := time():

> MatrixInverse( B );

> time()-st;

> Digits := 10;

> UseHardwareFloats := true;

MatrixInverse:   "calling external function"

MatrixInverse:   "NAG"   sw_f07adf

MatrixInverse:   "NAG"   sw_f07ajf

>

> st := time():

> P,L,U := LUDecomposition( A );

> time()-st;

>

> st := time():

> Lambda,U := Eigenvectors( B );

> time()-st;

Eigenvectors:   "calling external function"

Eigenvectors:   "copying first Matrix, to enable external call"

Eigenvectors:   "NAG"   hw_f02ebf

> map( Re, Lambda );

> map( Re, U );

>

>

> restart;

> with( LinearAlgebra );

>

> A := HilbertMatrix( 25 );

> B := evalf( A );

>

> st := time():

> MatrixInverse( A );

> time()-st;

>

> st := time():

> MatrixInverse( B );

> time()-st;

>

> UseHardwareFloats := false;

> Digits := 20;

> st := time():

> MatrixInverse( B );

> time()-st;

> Digits := 10;

> UseHardwareFloats := true;

>

> st := time():

> LUDecomposition( A );

> time()-st;

>

> st := time():

> Lambda,U := Eigenvectors( B );

> time()-st;

> map( Re, Lambda );

> map( Re, U );

>