Replacing calls to E02AEF

The equivalent of this routine in SLATEC is PDA_DP1VLU. The NAG code would look like

      INTEGER I, K, K2, NROWS, IFAIL
      DOUBLE PRECISION A1(NROWS,K+1)
      DOUBLE PRECISION A2(K2+1), XX, XCAP, P
      DO 1 I = 1, K2+1
         A2(I) = A1(K2+1,I)
    1 CONTINUE
      XCAP = ( ( XX - MIN(X()) ) - ( MAX(X()) - XX ) )
     :     / ( MAX(X()) - MIN(X()) )
      IFAIL = 1
      CALL E02AEF( K2+1, A2, XCAP, P, IFAIL )
      IF ( IFAIL .NE. 0 ) THEN
         An error has occurred
      END IF

Here A1 is the coefficient matrix returned by E02ADF, A2 is the column extracted for the required degree. XX is the x value for which an evaluation is required, it must be scaled into the range $-$1 ... +1, using the original extreme x values passed to E02ADF. P returns the function value.

PDA_DP1VLU returns any number of derivatives in addition to the function value. The second argument specifies how many derivatives are required. No scaling of XX is necessary, and no processing of the coefficients A3 as returned by PDA_DPOLFT.

      INTEGER K, K2, IFAIL
      DOUBLE PRECISION A3( 3*M + 3*(K+1) )
      DOUBLE PRECISION XX, P, DUMMY
      IFAIL = 0
      CALL PDA_DP1VLU( K2, 0, XX, P, DUMMY, A3, IFAIL )
      IF ( IFAIL .NE. 0 ) THEN
         An error has occurred
      END IF