Problem with "ceil"

[nicolas_martin]

Hello,

When I write

ceil(0.29999999999999, 0.1)

I expect

0.3

--> OK

When I write

ceil(0.3, 0.1)

I expect

0.3

--> OK

When I write

ceil(ceil(0.29999999999999, 0.1), 0.1)

I expect

0.3

--> KO, QlikView gives me

0.4

Because

ceil(0.29999999999999, 0.1)

returns in fact

0.30[...]01

Why?

ps: the workaround

ceil(0.299999 * 10) / 10

works.

[Gysbert_Wassenaar · Accepted solution]

See this blog post: Rounding Errors

[nicolas_martin]

I said

ps: the workaround

1. ceil(0.299999 * 10) / 10 

works.

but in facts, when I'm dealing with interval match, it doesn't work.

I have some calculated scores.

I want to round them to the upper 1/10th and apply to them a label:

Interval:

LOAD * INLINE [

From, Start, Label

0, 0, None

0.1, 0.3, Few

0.4, 1, Many

1.1, , Too much

];

Values:

LOAD

  *,

  //ceil(A / B, 0.1) AS Value

  ceil(A * 10 / B) / 10 AS Value

;

LOAD * INLINE [

Id, A, B

1, 0, 10

2, 1, 10

3, 29999, 100000

];

IM:

IntervalMatch (Value)

LOAD

  From,

  Start

RESIDENT Interval;

For my Id "3", the score is "29999 / 100000", that is "0.29999" that should be rounded at "0.3" (upper 1/10th), so the Label should be "Few".

But as the round workaround doesn't returns "0.3" nor "0.4" (but "0.30...01"), my line #3 has no Label