SLVBLK

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  S L V B L K   /  SOLUTION OF ALMOST-BLOCK-DIAGONAL LINEAR SYSTEMS
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  THIS PACKAGE CONSISTS OF A SINGLE FORTRAN SUBPROGRAM.
 
      SUBROUTINE SLVBLK ( BLOKS, INTEGS, NBLOKS, B, IPIVOT, X, IFLAG )
 
     THIS PROGRAM SOLVES  THE  LINEAR SYSTEM  A*X = B  WHERE A IS AN
   ALMOST BLOCK DIAGONAL MATRIX.  SUCH ALMOST BLOCK DIAGONAL MATRICES
   ARISE NATURALLY IN PIECEWISE POLYNOMIAL INTERPOLATION OR APPROX-
   IMATION AND IN FINITE ELEMENT METHODS FOR TWO-POINT BOUNDARY VALUE
   PROBLEMS.  THE PLU FACTORIZATION METHOD IS IMPLEMENTED HERE TO TAKE
   ADVANTAGE OF THE SPECIAL STRUCTURE OF SUCH SYSTEMS FOR SAVINGS IN
   COMPUTING TIME AND STORAGE REQUIREMENTS.
 
  AUTHORS:
    C. DE BOOR, MATH RESEARCH CENTER, UNIVERSITY OF WISCONSIN-MADISON
    A COMPLETE DESCRIPTION OF THE ALGORITHM IS CONTAINED IN THE PAPER
    BY THE SAME AUTHORS IN ACM TOMS V6, (MARCH 1980) PP 151.