This is driving me crazy. I know I
saw a way to do an "almost" comparison,
where "x == y +/- some delta". But I'm
hanged if I can find it. I've looked
everywhere...
On a related subject, when Ruby gives me
a File time, is it to the nearest second,
millisecond, or what, or is it O/S dependent?
The goal, of course, is to compare times
on two files to see if they are no more
than a second apart...
Eric Armstrong wrote:
This is driving me crazy. I know I
saw a way to do an "almost" comparison,
where "x == y +/- some delta". But I'm
hanged if I can find it. I've looked
everywhere...
Well, test/unit has assert_in_delta. Is that what you're thinking of? In any case, it seems to me that
(x - y).abs < delta
would do the trick quite neatly.
On a related subject, when Ruby gives me
a File time, is it to the nearest second,
millisecond, or what, or is it O/S dependent?
File#mtime and other File time methods return a normal Time object, which is O/S dependent but can be conveniently treated as a number of seconds.
The goal, of course, is to compare times
on two files to see if they are no more
than a second apart...
file_a = File.new("somefile")
file_b = File.new("someotherfile")
(file_a.mtime - file_b.mtime).abs < 1 ? puts "close" : puts "not close enough"
matthew smillie.
On Jun 10, 2006, at 1:10, Eric Armstrong wrote:
(t1.to_f - t2.to_f).abs < 1.0
#tv_sec will give it to you in integer seconds (same as #to_i)
#tv_usec will give you the fractional number of microseconds (stuff after the decimal point)
t1.tv_sec * 10**6 + t1.tv_usec should be the time in microseconds. (Divide it by 10.0**6 and you should get the the same thing as #to_f)
On Jun 9, 2006, at 8:10 PM, Eric Armstrong wrote:
This is driving me crazy. I know I
saw a way to do an "almost" comparison,
where "x == y +/- some delta". But I'm
hanged if I can find it. I've looked
everywhere...On a related subject, when Ruby gives me
a File time, is it to the nearest second,
millisecond, or what, or is it O/S dependent?The goal, of course, is to compare times
on two files to see if they are no more
than a second apart...
The time resolution is OS dependent. However, on Unix, the resolution is down to seconds. If you need to compare time, it's best to do so by first converting them to epoch time (seconds since 1/1/1970).
----- Original Message ----- From: "Logan Capaldo" <logancapaldo@gmail.com>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Sunday, June 11, 2006 3:26 PM
Subject: Re: Comparing times?
On Jun 9, 2006, at 8:10 PM, Eric Armstrong wrote:
This is driving me crazy. I know I
saw a way to do an "almost" comparison,
where "x == y +/- some delta". But I'm
hanged if I can find it. I've looked
everywhere...On a related subject, when Ruby gives me
a File time, is it to the nearest second,
millisecond, or what, or is it O/S dependent?The goal, of course, is to compare times
on two files to see if they are no more
than a second apart...(t1.to_f - t2.to_f).abs < 1.0
#tv_sec will give it to you in integer seconds (same as #to_i)
#tv_usec will give you the fractional number of microseconds (stuff after the decimal point)
t1.tv_sec * 10**6 + t1.tv_usec should be the time in microseconds. (Divide it by 10.0**6 and you should get the the same thing as #to_f)