Strange problem with numbers

[Thomas Grueninger]

Hello,

i have a strange Problem with numbers.

for n:=1.8 to 10.8 step .5
? str(n,22,18)
next

1.800000000000000000
2.300000000000000000
2.800000000000000000
3.300000000000000000
3.800000000000000000
4.300000000000000000
4.800000000000000000
5.300000000000000000
5.800000000000000000
6.300000000000000000
6.800000000000000000
7.300000000000000000
7.800000000000000000
8.300000000000001000
8.800000000000001000
9.300000000000001000
9.800000000000001000
10.300000000000000000
10.800000000000000000

Tested with xHarbour 1.2.3, BCC7 and xHarbour 1.2.0., BCC5
Same Result

Have anyone a solution?

Regards
Thomas Grueninger

[karinha]

maybe.

Code: Select all

#include "FiveWin.ch"

function Main()

   LOCAL N := 0

   for n:=1.8 to 10.8 step .5

      ? str(n,22,18)

      N = N + .1

   next

Return Nil

/*
1.800000000000000000
2.300000000000000000
2.800000000000000000
3.300000000000000000
3.800000000000000000
4.300000000000000000
4.800000000000000000
5.300000000000000000
5.800000000000000000
6.300000000000000000
6.800000000000000000
7.300000000000000000
7.800000000000000000
8.300000000000001000
8.800000000000001000
9.300000000000001000
9.800000000000001000
10.300000000000000000
10.800000000000000000
*/
 

[tiaofw]

Good Morning.

Full is a bug this xHarbour because this returning garbage in decimals.

It is good to inform xHarbour developers.

bye.

[Enrico Maria Giordano]

No, it's the normal behaviour of the floating-point numbers.

EMG

[tiaofw]

Enrico understood, then the solution would be to truncate the decimals?

I did not understand what the problem is that this variation is causing him.


Thanks

[Enrico Maria Giordano]

Better to round it to the desired number of decimals using ROUND() function.

EMG

[Thomas Grueninger]

It works simple. You never come to 8.8

local n:=8.8
MsgInfo(str(n,20,18))
---------------------------
Information
---------------------------
8.800000000000001000
---------------------------
OK
---------------------------

[Enrico Maria Giordano]

Clipper, Harbour, xHarbour floating-point system supports up to 15 significant digits.

EMG