calculations with currency

[Erich Schulman Member Find all posts View Profile Close Erich Schulman]

FUNCTION CalcMatch(A1 AS STRING, B1 AS STRING) AS STRING
LOCAL cA1,cB1,cMatch AS CURRENCY

    cA1 = VAL(A1) : cB1 = VAL(B1)

    'matching scenarios ladder up
    IF cB1 / cA1 <= 0.03# THEN '1st matching scenario
        FUNCTION = B1
        EXIT FUNCTION
    END IF

    IF cB1 / cA1 <= 0.05# THEN '2nd matching scenario
        cMatch = cA1 * 0.03# + cA1*(cB1/cA1-0.03#) * 0.5#
        FUNCTION = FORMAT$(cMatch,"#####.00")
        EXIT FUNCTION
    END IF

    cMatch = cA1 * 0.04# '3rd matching scenario
    FUNCTION = FORMAT$(cMatch,"#####.00")
END FUNCTION

For the most accurate results, should I change the numeric literals from DOUBLE to EXTENDED or CURRENCY, or is DOUBLE adequate?

[Bob Zale Creator of PowerBASIC Find all posts View Profile Close Bob Zale]

EXT would be the best choice.

[John Gleason Member Find all posts View Profile Close John Gleason]

Erich, do you have PB 9/5? If so, then you can use eg. 0.03## to convert them to EXT.

[Michael Mattias Member Find all posts View Profile Close Michael Mattias]

In the example given it's moot, since no intermediate value requires more than 4 positions after the decimal, meaning you never get into rounding at all.

FWIW, I use CUR for all money stuff and never have any problems.

[added]
Except for the division.


MCM