PROCEDURE mtt_ludcmp(VAR a: StateMatrix; n: integer;
VAR indx: StateVector; VAR d: real);
{ This file is derived from the NUMERICAL RECIPES PASCAL SHAREWARE DISKETTE.
Please read the README file in $MTTPATH/trans/p
}
{
###############################################################
## Version control history
###############################################################
## $Id$
## $Log$
## Revision 1.1 1998/08/14 07:58:13 peterg
## Initial revision
##
###############################################################
}
(* Programs using LUDCMP must define the types
TYPE
glnpbynp = ARRAY [1..np,1..np] OF real;
glnarray = ARRAY [1..n] OF real;
glindx = ARRAY [1..n] OF integer;
in the main routine. *)
CONST
tiny=1.0e-20;
VAR
k,j,imax,i: integer;
sum,dum,big: real;
vv: glnarray;
BEGIN
d := 1.0;
FOR i := 1 TO n DO BEGIN
big := 0.0;
FOR j := 1 TO n DO IF (abs(a[i,j]) > big) THEN big := abs(a[i,j]);
IF (big = 0.0) THEN BEGIN
writeln('pause in LUDCMP - singular matrix'); readln
END;
vv[i] := 1.0/big
END;
FOR j := 1 TO n DO BEGIN
FOR i := 1 TO j-1 DO BEGIN
sum := a[i,j];
FOR k := 1 TO i-1 DO BEGIN
sum := sum-a[i,k]*a[k,j]
END;
a[i,j] := sum
END;
big := 0.0;
FOR i := j TO n DO BEGIN
sum := a[i,j];
FOR k := 1 TO j-1 DO BEGIN
sum := sum-a[i,k]*a[k,j]
END;
a[i,j] := sum;
dum := vv[i]*abs(sum);
IF (dum > big) THEN BEGIN
big := dum;
imax := i
END
END;
IF (j <> imax) THEN BEGIN
FOR k := 1 TO n DO BEGIN
dum := a[imax,k];
a[imax,k] := a[j,k];
a[j,k] := dum
END;
d := -d;
vv[imax] := vv[j]
END;
indx[j] := imax;
IF (a[j,j] = 0.0) THEN a[j,j] := tiny;
IF (j <> n) THEN BEGIN
dum := 1.0/a[j,j];
FOR i := j+1 TO n DO BEGIN
a[i,j] := a[i,j]*dum
END
END
END;
END;