NUMAL Section 3.1.2.1.1.1.1.2

BEGIN SECTION : 3.1.2.1.1.1.1.2 (June, 1974)

CONTRIBUTOR    :    J. KOK.

INSTITUTE      :    MATHEMATICAL CENTRE.

RECEIVED       :    730903.

BRIEF DESCRIPTION  :

    THIS SECTION CONTAINS THE PROCEDURE DETERMBND
    FOR THE CALCULATION OF THE DETERMINANT OF A BAND MATRIX.

KEY WORDS  :

    DETERMINANT,
    BAND MATRIX.

CALLING SEQUENCE       :

    THE HEADING OF THE PROCEDURE IS    :

    "REAL""PROCEDURE" DETERMBND(A, N, LW, RW, SGNDET); "VALUE" N, LW,
    RW, SGNDET; "INTEGER" N, LW, RW, SGNDET; "ARRAY" A;
    "CODE" 34321;

    DETERMBND DELIVERS THE DETERMINANT OF THE MATRIX.

    THE MEANING OF THE FORMAL PARAMETERS IS    :

    A, N, LW, RW   :    SEE 'CALLING SEQUENCE' OF DECBND
                (SECTION 3.1.2.1.1.1.1.1.);
                ENTRY : THE CONTENTS OF A ARE AS PRODUCED BY DECBND OR
                DECSOLBND (SECTION 3.1.2.1.1.1.1.3.);
    SGNDET  :   <ARITHMETIC EXPRESSION>;
                ENTRY : THE SIGN OF THE DETERMINANT AS DELIVERED IN
                AUX[1] BY DECBND, IF THE ELIMINATION BY DECBND WAS
                SUCCESSFUL.

PROCEDURES USED    :    NONE.

RUNNING TIME   :    PROPORTIONAL TO N.

LANGUAGE       :    ALGOL 60.

METHOD AND PERFORMANCE :

    DETERMBND CAN BE CALLED AFTER DECBND OR DECSOLBND ONLY IF THE
    GAUSSIAN ELIMINATION WAS SUCCESSFUL, I.E. IF AUX[3] = N.
    THE FUNCTION VALUE OF DETERMBND IS
    THE DETERMINANT OF THE GAUSSIAN ELIMINATED UPPER TRIANGULAR
    MATRIX PROVIDED WITH THE CORRECT SIGN THAT IS DELIVERED BY
    DECBND OR DECSOLBND IN AUX[1].
    DETERMBND SHOULD NOT BE CALLED WHEN OVERFLOW CAN BE EXPECTED.

EXAMPLE OF USE :

    SEE EXAMPLES OF USE OF SOLBND AND DECSOLBND.

SOURCE TEXT(S) :
"CODE" 34321;