[lnkForumImage]
TotalShareware - Download Free Software
Confronta i prezzi di migliaia di prodotti.
Asp Forum
 Home | Login | Register | Search 


 

Forums >

comp.lang.ruby

Noob devision question

jamiethehutt

7/25/2006 7:04:00 PM

I'm trying to make a percentage progress bar for an XMMS web interface,
I want to take the total track time and the elapsed time and then make
a length for the bar from the percentage completed.

something like:

totalbarsize = 180
timeelapsed = 10
totaltime = 30

percomplete = 0.0
barlength = 0.0

percomplete = timeelapsed / totaltime
barlength = totalbarsize*percomplete

puts barlength

Now that should give me a barlength of 60 pixels but it gives 0
instead. Anyone know what I'm doing wrong?

Thanks!

(I'll forget that I need barlength as an integer rather than a float
for now :-P)
7 Answers

Justin Collins

7/25/2006 7:11:00 PM

0

jamiethehutt wrote:
> I'm trying to make a percentage progress bar for an XMMS web interface,
> I want to take the total track time and the elapsed time and then make
> a length for the bar from the percentage completed.
>
> something like:
>
> totalbarsize = 180
> timeelapsed = 10
> totaltime = 30
>
> percomplete = 0.0
> barlength = 0.0
>
> percomplete = timeelapsed / totaltime
> barlength = totalbarsize*percomplete
>
> puts barlength
>
> Now that should give me a barlength of 60 pixels but it gives 0
> instead. Anyone know what I'm doing wrong?
>
> Thanks!
>
> (I'll forget that I need barlength as an integer rather than a float
> for now :-P)
>
>
>

timeelapsed and totaltime are Integers. So when you divide them, it does
integer division:

irb(main):001:0> 10/30
=> 0
irb(main):002:0> 10.0 / 30.0
=> 0.333333333333333


try

percomplete = timeelapsed.to_f / totaltime

or

percomplete = timeelapsed / totaltime.to_f

or

percomplete = timeelapsed.to_f / totaltime.to_f

or

totaltime = 30.0
timeelapsed = 10.0

You get the idea :) Floats for floating point division.

-Justin

Timothy Bennett

7/25/2006 7:13:00 PM

0

Division of 2 integers results in an integer. So, try setting
timeelapsed to 10.0 instead of 10.

Tim

Chris Hulan

7/25/2006 7:13:00 PM

0

jamiethehutt wrote:
....
> totalbarsize = 180
> timeelapsed = 10
> totaltime = 30
>
> percomplete = 0.0
> barlength = 0.0
>
> percomplete = timeelapsed / totaltime
> barlength = totalbarsize*percomplete
>
> puts barlength

You need Floats all the way down.
The division of Fixnum values ( timeelapsed / totaltime)
produces a Fixnum value, which is 0 as 0.333 gets truncated

put a .0 after all the non-Float values to force them to be Float

Tom Rauchenwald

7/25/2006 7:17:00 PM

0

"jamiethehutt" <jamie@annforfungi.co.uk> writes:

> I'm trying to make a percentage progress bar for an XMMS web interface,
> I want to take the total track time and the elapsed time and then make
> a length for the bar from the percentage completed.
>
> something like:
>
> totalbarsize = 180
> timeelapsed = 10
> totaltime = 30
>
> percomplete = 0.0
> barlength = 0.0
>
> percomplete = timeelapsed / totaltime

This is an integer-division, and since totaltime is always bigger than
timeelapsed (in theory ;-) it is always 0.
You could try defining totaltime as 30.0 initially or write it as
percomplete = timeelapsed.to_f / totaltime
or something.

> barlength = totalbarsize*percomplete
>
> puts barlength
>
> Now that should give me a barlength of 60 pixels but it gives 0
> instead. Anyone know what I'm doing wrong?
>
> Thanks!

Tom

Chris Hulan

7/25/2006 7:18:00 PM

0


ChrisH wrote:
> jamiethehutt wrote:
> ...
> > totalbarsize = 180
> > timeelapsed = 10
> > totaltime = 30
> >
> > percomplete = 0.0
> > barlength = 0.0
> >
> > percomplete = timeelapsed / totaltime
> > barlength = totalbarsize*percomplete
> >
> > puts barlength
>
> You need Floats all the way down.
> The division of Fixnum values ( timeelapsed / totaltime)
> produces a Fixnum value, which is 0 as 0.333 gets truncated
>
> put a .0 after all the non-Float values to force them to be Float

Fogot to say, to get an Integer (or Fixnum id Ruby parlance) just call
to_i on the Float value to covert by truncating the value.

cheers

William James

7/25/2006 8:21:00 PM

0


jamiethehutt wrote:
> I'm trying to make a percentage progress bar for an XMMS web interface,
> I want to take the total track time and the elapsed time and then make
> a length for the bar from the percentage completed.
>
> something like:
>
> totalbarsize = 180
> timeelapsed = 10
> totaltime = 30
>
> percomplete = 0.0
> barlength = 0.0
>
> percomplete = timeelapsed / totaltime
> barlength = totalbarsize*percomplete
>
> puts barlength
>
> Now that should give me a barlength of 60 pixels but it gives 0
> instead. Anyone know what I'm doing wrong?
>
> Thanks!
>
> (I'll forget that I need barlength as an integer rather than a float
> for now :-P)

>> 10/30
=> 0
>> 10*100/30
=> 33

Morton Goldberg

7/25/2006 9:08:00 PM

0

Use quo. For example:

percomplete = timeelapsed.quo(totaltime) => 0.333333333333333

Regards, Morton

On Jul 25, 2006, at 3:05 PM, jamiethehutt wrote:

> I'm trying to make a percentage progress bar for an XMMS web
> interface,
> I want to take the total track time and the elapsed time and then make
> a length for the bar from the percentage completed.
>
> something like:
>
> totalbarsize = 180
> timeelapsed = 10
> totaltime = 30
>
> percomplete = 0.0
> barlength = 0.0
>
> percomplete = timeelapsed / totaltime
> barlength = totalbarsize*percomplete
>
> puts barlength
>
> Now that should give me a barlength of 60 pixels but it gives 0
> instead. Anyone know what I'm doing wrong?
>
> Thanks!
>
> (I'll forget that I need barlength as an integer rather than a float
> for now :-P)
>
>