help with FLOATS..

[Maky]

Hi folks
I have the following code in my program. The aim is to generate a sense of time, like 1.01, 1.02.. 1.60 ,2.01 etc..

for (float x = 0 ; x < 20 ; x++) {
for (float i = 1 ; i < 60 ; i++){
float y = x + i/100;
System.out.println(y) ;
}
}

This gives me some strange errors like :
1.16
1.17
1.1800001
1.19
1.2
1.21
1.22
1.23
1.24
1.25
1.26
1.27
1.28
1.29
1.3
1.31
1.3199999
1.33
Any idea why this is happening ??
[This message has been edited by Maky (edited December 21, 2001).]

[Manfred Leonhardt]

Hi Maky,
It is called round-off error. Anytime you are printing float or double values you should format the results if it is important to you. Look at:
java.text.DecimalFormat
For example:
DecimalFormat df = new DecimalFormat( "#.00" );
System.out.prnitln( df.format( y ) );
will make your output look consistent.
Regards,
Manfred.

[Cindy Glass]

Hi Maky,
Surely we have had this talk before - but can you PLEASE re-register with a name that fits the JavaRanch's naming policy.
Your ID should be 2 separate names with more than 1 letter each. We really want this to be a professional forum and would prefer that you use your REAL name.
Thanks,
Cindy

[Corey McGlone]

double f = 5.1111111111111112;
double g = 5.1111111111111113;
if ( f == g )
   System.out.println("OK");
else
   System.out.println("Nope");

Running this results in "OK" being printed. Precise, sure, perfect, nope.
Corey
[This message has been edited by Corey McGlone (edited December 21, 2001).]