RosettaCodeData/Task/Arithmetic-geometric-mean/COBOL/arithmetic-geometric-mean.cobol
2016-12-05 22:15:40 +01:00

33 lines
1 KiB
COBOL

IDENTIFICATION DIVISION.
PROGRAM-ID. ARITHMETIC-GEOMETRIC-MEAN-PROG.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 AGM-VARS.
05 A PIC 9V9(16).
05 A-ZERO PIC 9V9(16).
05 G PIC 9V9(16).
05 DIFF PIC 9V9(16) VALUE 1.
* Initialize DIFF with a non-zero value, otherwise AGM-PARAGRAPH
* is never performed at all.
PROCEDURE DIVISION.
TEST-PARAGRAPH.
MOVE 1 TO A.
COMPUTE G = 1 / FUNCTION SQRT(2).
* The program will run with the test values. If you would rather
* calculate the AGM of numbers input at the console, comment out
* TEST-PARAGRAPH and un-comment-out INPUT-A-AND-G-PARAGRAPH.
* INPUT-A-AND-G-PARAGRAPH.
* DISPLAY 'Enter two numbers.'
* ACCEPT A.
* ACCEPT G.
CONTROL-PARAGRAPH.
PERFORM AGM-PARAGRAPH UNTIL DIFF IS LESS THAN 0.000000000000001.
DISPLAY A.
STOP RUN.
AGM-PARAGRAPH.
MOVE A TO A-ZERO.
COMPUTE A = (A-ZERO + G) / 2.
MULTIPLY A-ZERO BY G GIVING G.
COMPUTE G = FUNCTION SQRT(G).
SUBTRACT A FROM G GIVING DIFF.
COMPUTE DIFF = FUNCTION ABS(DIFF).