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- PROGRAM DSin; { ported from Fortran original 05-01-92 Norbert Juffa }
-
- {$A+,B-,D-,E+,F-,G-,I-,L-,N-,O-,R-,S-,V-,X-}
-
- USES MachArit, Power;
-
- {
- C PROGRAM TO TEST DSIN/DCOS
- C
- C DATA REQUIRED
- C
- C NONE
- C
- C SUBPROGRAMS REQUIRED FROM THIS PACKAGE
- C
- C MACHAR - AN ENVIRONMENTAL INQUIRY PROGRAM PROVIDING
- C INFORMATION ON THE FLOATING-POINT ARITHMETIC
- C SYSTEM. NOTE THAT THE CALL TO MACHAR CAN
- C BE DELETED PROVIDED THE FOLLOWING FIVE
- C PARAMETERS ARE ASSIGNED THE VALUES INDICATED
- C
- C IBETA - THE RADIX OF THE FLOATING-POINT SYSTEM
- C IT - THE NUMBER OF BASE-IBETA DIGITS IN THE
- C SIGNIFICAND OF A FLOATING-POINT NUMBER
- C MINEXP - THE LARGEST IN MAGNITUDE NEGATIVE
- C INTEGER SUCH THAT DFLOAT(IBETA)**MINEXP
- C IS A POSITIVE FLOATING-POINT NUMBER
- C EPS - THE SMALLEST POSITIVE FLOATING-POINT
- C NUMBER SUCH THAT 1.0+EPS .NE. 1.0
- C EPSNEG - THE SMALLEST POSITIVE FLOATING-POINT
- C NUMBER SUCH THAT 1.0-EPSNEG .NE. 1.0
- C
- C REN(K) - A FUNCTION SUBPROGRAM RETURNING RANDOM REAL
- C NUMBERS UNIFORMLY DISTRIBUTED OVER (0,1)
- C
- C
- C STANDARD FORTRAN SUBPROGRAMS REQUIRED
- C
- C DABS, DLOG, DMAX1, DCOS, DLOAT, DSIN, DSQRT
- C
- C
- C LATEST REVISION - DECEMBER 6, 1979
- C
- C AUTHOR - W. J. CODY
- C ARGONNE NATIONAL LABORATORY
- C
- C
- }
-
-
- FUNCTION REN (VAR K: LONGINT): REAL;
-
- {
- DOUBLE PRECISION FUNCTION REN(K)
- C
- C RANDOM NUMBER GENERATOR - BASED ON ALGORITHM 266 BY PIKE AND
- C HILL (MODIFIED BY HANSSON), COMMUNICATIONS OF THE ACM,
- C VOL. 8, NO. 10, OCTOBER 1965.
- C
- C THIS SUBPROGRAM IS INTENDED FOR USE ON COMPUTERS WITH
- C FIXED POINT WORDLENGTH OF AT LEAST 29 BITS. IT IS
- C BEST IF THE FLOATING POINT SIGNIFICAND HAS AT MOST
- C 29 BITS.
- C
- }
-
- VAR J: LONGINT;
- CONST IY: LONGINT = 100001;
-
- BEGIN
- J := K;
- IY := IY * 125;
- IY := IY - (IY DIV 2796203) * 2796203;
- REN:= 1.0 * (IY) / 2796203.0e0 * (1.0e0 + 1.0e-6 + 1.0e-12);
- END;
-
-
-
- FUNCTION MAX1 (A, B:REAL): REAL;
- BEGIN
- IF A > B THEN
- MAX1 := A
- ELSE
- MAX1 := B;
- END;
-
-
-
- VAR I,IBETA,IEXP,IOUT,IRND,IT,I1,J, K1,K2,
- K3,MACHEP,MAXEXP,MINEXP,N,NEGEP,NGRD: LONGINT;
-
- A,AIT,ALBETA,B,BETA,C,DEL,EPS,EPSNEG,HALF,ONE,
- T,THREE,BETAP,TEMP,EXPON,R6,R7,TENTH,W,X,XL,PI,
- XMAX,XMIN,XN,X1,Y,Z,ZERO,ZZ,THREEFOURTH,FOUR,SIX: REAL;
-
- LABEL 100, 110, 120, 150, 160, 210, 220, 230, 240, 300;
-
-
- BEGIN
-
- N := 1000000; { number of trials }
-
- MACHAR (IBETA,IT,IRND,NGRD,MACHEP,NEGEP,IEXP,MINEXP,MAXEXP,
- EPS,EPSNEG,XMIN,XMAX);
- PRINTPARAM (IBETA,IT,IRND,NGRD,MACHEP,NEGEP,IEXP,MINEXP,MAXEXP,
- EPS,EPSNEG,XMIN,XMAX);
- BETA := IBETA;
- ALBETA := LN (BETA);
- AIT := IT;
- ZERO := 0;
- ONE := 1;
- THREE := 3;
- FOUR := 4;
- SIX := 6;
- HALF := 0.5;
- THREEFOURTH:= 0.75;
- PI := 3.14159265358979323846264338327950288;
- A := ZERO;
- B := HALF*PI;
- C := B;
- XN := N;
- I1 := 0;
-
- {-----------------------------------------------------------------}
- { RANDOM ARGUMENT ACCURACY TESTS }
- {-----------------------------------------------------------------}
-
- FOR J := 1 TO 3 DO BEGIN
- K1 := 0;
- K3 := 0;
- X1 := ZERO;
- R6 := ZERO;
- R7 := ZERO;
- DEL:= (B - A) / XN;
- XL := A;
-
- FOR I := 1 TO N DO BEGIN
- X := DEL * REN (I1) + XL;
- Y := X / THREE;
- Y := (X + Y);
- Y := Y - X;
- X := THREE * Y;
- IF J = 3 THEN
- GOTO 100;
- Z := SIN (X);
- ZZ:= SIN (Y);
- W := ONE;
- IF Z <> ZERO THEN BEGIN
- TEMP := FOUR * ZZ * ZZ;
- TEMP := THREE - TEMP;
- TEMP := ZZ * TEMP;
- TEMP := Z - TEMP;
- W := TEMP / Z;
- END;
- GOTO 110;
- 100: Z := COS (X);
- ZZ := COS (Y);
- W := ONE;
- IF Z <> ZERO THEN BEGIN
- TEMP := FOUR * ZZ * ZZ;
- TEMP := THREE - TEMP;
- TEMP := ZZ * TEMP;
- TEMP := Z + TEMP;
- W := TEMP / Z;
- END;
- 110: IF W > ZERO THEN
- K1 := K1 + 1;
- IF W < ZERO THEN
- K3 := K3 + 1;
- W := ABS(W);
- IF W <= R6 THEN
- GOTO 120;
- R6 := W;
- X1 := X;
- 120: R7 := R7 + W * W;
- XL := XL + DEL;
- END;
-
- K2 := N - K3 - K1;
- R7 := SQRT (R7/XN);
-
- IF J = 3 THEN
- GOTO 210;
- WRITELN;
- WRITELN;
- WRITELN ('TEST OF SIN(X) VS 3*SIN(X/3)-4*SIN(X/3)**3');
- WRITELN;
- WRITELN (N, ' RANDOM ARGUMENTS WERE TESTED FROM THE INTERVAL');
- WRITELN ('(', A, ',', B, ')');
- WRITELN;
- inline ($fa/$fb);
- WRITELN ('SIN (X) WAS LARGER', K1:6, ' TIMES');
- WRITELN (' AGREED', K2:6, ' TIMES');
- WRITELN (' AND WAS SMALLER', K3:6, ' TIMES');
- GOTO 220;
- 210: WRITELN;
- WRITELN;
- WRITELN ('TEST OF COS(X) VS 4*COS(X/3)**3-3*COS(X/3)');
- WRITELN;
- WRITELN (N, ' RANDOM ARGUMENTS WERE TESTED FROM THE INTERVAL');
- WRITELN ('(', A, ',', B, ')');
- WRITELN;
- WRITELN ('COS (X) WAS LARGER', K1:6, ' TIMES');
- WRITELN (' AGREED', K2:6, ' TIMES');
- WRITELN (' AND WAS SMALLER', K3:6, ' TIMES');
- 220: WRITELN;
- WRITELN ('THERE ARE ', IT, ' BASE ', IBETA,
- ' SIGNIFICANT DIGITS IN A FLOATING-POINT NUMBER');
- WRITELN;
- W := -999.0;
- IF R6 <> ZERO THEN
- W := LN (ABS(R6))/ALBETA;
- WRITELN ('THE MAXIMUM RELATIVE ERROR OF ', R6:12,
- ' = ', IBETA, ' **', W:7:2);
- WRITELN ('OCCURED FOR X = ', X1);
- W := MAX1 (AIT+W, ZERO);
- WRITELN;
- WRITELN ('THE ESTIMATED LOSS OF BASE ', IBETA,
- ' SIGNIFICANT DIGITS IS ', W:7:2);
- W := -999.0;
- IF R7 <> ZERO THEN
- W := LN (ABS(R7))/ALBETA;
- WRITELN;
- WRITELN ('THE ROOT MEAN SQUARE RELATIVE ERROR WAS', R7:12,
- ' = ', IBETA, ' **' , W:7:2);
- W := MAX1 (AIT+W,ZERO);
- WRITELN;
- WRITELN ('THE ESTIMATED LOSS OF BASE ', IBETA,
- ' SIGNIFICANT DIGITS IS ', W:7:2);
- A := SIX * PI;
- IF J = 2 THEN
- A := B + C;
- B := A + C;
- END;
-
- {-----------------------------------------------------------------}
- { SPECIAL TESTS }
- {-----------------------------------------------------------------}
-
- WRITELN;
- WRITELN;
- WRITELN ('SPECIAL TESTS');
- WRITELN;
- C := ONE / POW (BETA, (IT/2));
- Z := SIN (A+C);
- Z := Z - SIN (A-C);
- TEMP := C + C;
- Z := Z / TEMP;
- WRITELN ('IF ',Z:18,' IS NOT ALMOST 1.0, SIN HAS THE WRONG PERIOD.');
-
- WRITELN;
- WRITELN;
- WRITELN ('THE IDENTITY SIN(-X) = -SIN(X) WILL BE TESTED.');
- WRITELN;
- WRITELN (' F(X) F(X)+F(-X)');
- WRITELN;
-
- FOR I := 1 TO 5 DO BEGIN
- X := REN(I1) * A;
- Z := SIN(X) + SIN(-X);
- WRITELN (X:18, Z:18);
- END;
-
- WRITELN;
- WRITELN;
- WRITELN ('THE IDENTITY SIN(X) = X , X SMALL, WILL BE TESTED.');
- WRITELN;
- WRITELN (' X X-F(X)');
- WRITELN;
- BETAP := POW (BETA, IT);
- X := REN(I1) / BETAP;
-
- FOR I := 1 TO 5 DO BEGIN
- Z := X - SIN(X);
- WRITELN (X:18, Z:18);
- X := X / BETA;
- END;
-
- WRITELN;
- WRITELN;
- WRITELN ('THE IDENTITY COS(-X) = COS(X) WILL BE TESTED.');
- WRITELN;
- WRITELN (' X F(X)-F(-X)');
- WRITELN;
- FOR I := 1 TO 5 DO BEGIN
- X := REN (I1) * A;
- Z := COS (X) - COS (-X);
- WRITELN (X:18, Z:18);
- END;
-
- WRITELN;
- WRITELN;
- WRITELN ('TEST OF UNDERFLOW FOR VERY SMALL ARGUMENT.');
- WRITELN;
- EXPON := MINEXP * THREEFOURTH;
- X := POW (BETA, EXPON);
- Y := SIN (X);
- WRITELN ('SIN (', X:15, ') = ', Y:15);
- WRITELN;
- WRITELN ('THE FOLLOWING THREE LINES ILLUSTRATE THE LOSS IN SIGNIFICANCE');
- WRITELN ('FOR LARGE ARGUMENTS. THE ARGUMENTS ARE CONSECUTIVE.');
- WRITELN;
- Z := SQRT (BETAP);
- X := Z * (ONE - EPSNEG);
- Y := SIN(X);
- WRITELN ('SIN (', X:15, ') = ', Y:15);
- Y := SIN(Z);
- WRITELN ('SIN (', X:15, ') = ', Y:15);
- X := Z * (ONE + EPS);
- Y := SIN(X);
- WRITELN ('SIN (', X:15, ') = ', Y:15);
-
- {-----------------------------------------------------------------}
- { TEST OF ERROR RETURNS }
- {-----------------------------------------------------------------}
-
- WRITELN;
- WRITELN;
- WRITELN ('TEST OF ERROR RETURNS');
- WRITELN;
- X := BETAP;
- WRITELN ('SIN WILL BE CALLED WITH THE ARGUMENT ', X:15);
- WRITELN ('THIS SHOULD TRIGGER AN ERROR MESSAGE');
- Y := SIN(X);
- WRITELN ('SIN RETURNED THE VALUE ', Y:15);
- WRITELN;
- WRITELN ('THIS CONCLUDES THE TESTS');
- END. { DSin }