*DECK SDF SUBROUTINE SDF (N, T, Y, YP) C***BEGIN PROLOGUE SDF C***SUBSIDIARY C***PURPOSE Quick check for SLATEC routines SDRIV1, SDRIV2 and SDRIV3. C***LIBRARY SLATEC (SDRIVE) C***CATEGORY I1A2, I1A1B C***TYPE SINGLE PRECISION (SDF-S, DDF-D, CDF-C) C***KEYWORDS QUICK CHECK, SDRIV1, SDRIV2, SDRIV3 C***AUTHOR Kahaner, D. K., (NIST) C National Institute of Standards and Technology C Gaithersburg, MD 20899 C Sutherland, C. D., (LANL) C Mail Stop D466 C Los Alamos National Laboratory C Los Alamos, NM 87545 C***SEE ALSO SDQCK C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 890405 DATE WRITTEN C 890405 Revised to meet SLATEC standards. C***END PROLOGUE SDF REAL ALFA, T, Y(*), YP(*) INTEGER N C***FIRST EXECUTABLE STATEMENT SDF ALFA = Y(N+1) YP(1) = 1.E0 + ALFA*(Y(2) - Y(1)) - Y(1)*Y(3) YP(2) = ALFA*(Y(1) - Y(2)) - Y(2)*Y(3) YP(3) = 1.E0 - Y(3)*(Y(1) + Y(2)) RETURN END