Hi,

Firebird v2.5

Can anyone explain why the following example gives inconsistent
results. The first two I consider correct (rounded up to 8.42),
the last four I consider incorrect (rounded down to 8.41).


EXECUTE BLOCK
RETURNS (
"Result" DOUBLE PRECISION
) AS
DECLARE A DOUBLE PRECISION;
DECLARE B DOUBLE PRECISION;
DECLARE C DOUBLE PRECISION;
BEGIN
A = 170.0;
B = 4.95;
C = 100.0;

"Result" = round( a * (b / c), 2 );
SUSPEND;
"Result" = a * (b / c);
"Result" = round("Result", 2);
SUSPEND;

"Result" = round( a * b / c, 2 );
SUSPEND;
"Result" = a * b / c;
"Result" = round("Result", 2);
SUSPEND;

"Result" = round( (a * b) / c, 2 );
SUSPEND;
"Result" = (a * b) / c;
"Result" = round("Result", 2);
SUSPEND;
END


I was changing over from a UDF of my own that used an explicitly
DOUBLE PRECISION input parameter. When I use that UDF in the
above code, all results return the same 8.42 value.

--
Geoff Worboys
Telesis Computing Pty Ltd