C-----------------------------------------------------------------------
C IMSL Name:  EVCSB/DEVCSB (Single/Double precision version)
C
C Purpose:    Compute all of the eigenvalues and eigenvectors of a
C             real symmetric matrix in band symmetric storage mode.
C
C Usage:      CALL EVCSB (N, A, LDA, NCODA, EVAL, EVEC, LDEVEC)
C
C Example 1:
C                                  Declare variables
      INTEGER    LDA, LDEVEC, N, NCODA
      PARAMETER  (N=6, NCODA=2, LDA=NCODA+1, LDEVEC=N)
C
      INTEGER    NOUT
      REAL       A(LDA,N), EPISB, EVAL(N), EVEC(LDEVEC,N), PI
      EXTERNAL   EPISB, EVCSB, UMACH, WRRRN
C                                  Define values of A:
C                                  A = (  5  -4   1              )
C                                      ( -4   6  -4   1          )
C                                      (  1  -4   6  -4   1      )
C                                      (      1  -4   6  -4   1  )
C                                      (          1  -4   6  -4  )
C                                      (              1  -4   5  )
C                                  Represented in band symmetric
C                                  form this is:
C                                  A = (  0   0   1   1   1   1  )
C                                      (  0  -4  -4  -4  -4  -4  )
C                                      (  5   6   6   6   6   5  )
C
      DATA A/0.0, 0.0, 5.0, 0.0, -4.0, 6.0, 1.0, -4.0, 6.0, 1.0, -4.0,
     &     6.0, 1.0, -4.0, 6.0, 1.0, -4.0, 5.0/
C
C                                  Find eigenvalues and vectors
      CALL EVCSB (N, A, LDA, NCODA, EVAL, EVEC, LDEVEC)
C                                  Compute performance index
      PI = EPISB(N,N,A,LDA,NCODA,EVAL,EVEC,LDEVEC)
C                                  Print results
      CALL UMACH (2, NOUT)
      CALL WRRRN ('EVAL', 1, N, EVAL, 1, 0)
      CALL WRRRN ('EVEC', N, N, EVEC, LDEVEC, 0)
      WRITE (NOUT,'(/,A,F6.3)') ' Performance index = ', PI
      END
C
C                       EVAL
C       1       2       3       4       5       6
C   14.45   10.54    5.98    2.42    0.57    0.04
C
C                           EVEC
C           1        2        3        4        5        6
C  1  -0.2319  -0.4179  -0.5211   0.5211  -0.4179   0.2319
C  2   0.4179   0.5211   0.2319   0.2319  -0.5211   0.4179
C  3  -0.5211  -0.2319   0.4179  -0.4179  -0.2319   0.5211
C  4   0.5211  -0.2319  -0.4179  -0.4179   0.2319   0.5211
C  5  -0.4179   0.5211  -0.2319   0.2319   0.5211   0.4179
C  6   0.2319  -0.4179   0.5211   0.5211   0.4179   0.2319
C
C  Performance index =  0.029