*DECK DFQD1 DOUBLE PRECISION FUNCTION DFQD1 (X) C***BEGIN PROLOGUE DFQD1 C***SUBSIDIARY C***PURPOSE Function evaluator for DQNC79 and DGAUS8 quick checks. C***LIBRARY SLATEC C***TYPE DOUBLE PRECISION (FQD1-S, DFQD1-D) C***AUTHOR Boland, W. Robert, (LANL) C***SEE ALSO DQG8TS, DQN79Q C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 920229 DATE WRITTEN C***END PROLOGUE DFQD1 C .. Scalar Arguments .. DOUBLE PRECISION X C .. Intrinsic Functions .. INTRINSIC SQRT C***FIRST EXECUTABLE STATEMENT DFQD1 DFQD1 = 0.0D0 IF (X .GT. 0.0D0) THEN DFQD1 = 1.0D0/SQRT(X) ENDIF RETURN END