On 2005-12-08, Bengt Richter <[EMAIL PROTECTED]> wrote:
>>We're seeing floating point representation issues.
>>
>>The resolution of the underlying call is exactly 1us. Calling
>>gettimeofday() in a loop in C results in deltas of exactly 1 or
>>2 us. Python uses a C double to represent time, an
On Wed, 07 Dec 2005 18:32:50 -, Grant Edwards <[EMAIL PROTECTED]> wrote:
>On 2005-12-07, Fredrik Lundh <[EMAIL PROTECTED]> wrote:
...
>> if I keep running the script over and over again, I do get individual
>>
>> -1.19209289551e-06
>>
>> items from time to time on both machines...
>
>We're see
On 2005-12-07, Fredrik Lundh <[EMAIL PROTECTED]> wrote:
>> import time
>> for i in range(10):
>> print time.time()-time.time()
>>
>> After the first loop, I usually get one of three values:
>>
>> 3.099us, 2.14,us, 2.86us.
>
> I get two different values:
>
> -1.90734863281e-06
> -2.1457672119
Peter Hansen wrote:
> Fredrik Lundh wrote:
>>Peter Hansen wrote:
>>>Going by memory, Linux will generally be 1ms resolution (I might be
>>>off by 10 there...), while Windows XP has about 64 ticks per second,
>>>so .015625 resolution...
>
>>if I run this on the Windows 2K box I'm sitting at right n
Grant Edwards wrote:
> > Yeah, I said it was silly. On the other hand, the Linux box is a lot faster
> > than the Windows box I'm using, and I do get the same result no matter
> > what Python version I'm using...
except if I run it under my latest 2.4 build, where I get 524288 ...
> >
> > (and
Fredrik Lundh wrote:
> if I run this on the Windows 2K box I'm sitting at right now, it settles
> at 100 for time.time, and 1789772 for time.clock. on linux, I get 100
> for time.clock instead, and 262144 for time.time.
Aren't the time.clock semantics different on 'nix? I thought, at least
on
Peter Hansen wrote:
> A few things.
>
> 1. "Precision" is probably the wrong word there. "Resolution" seems
> more correct.
>
> 2. If your system returns figures after the decimal point, it probably
> has better resolution than one second (go figure). Depending on what
> system it is, your b
Fredrik Lundh wrote:
> Peter Hansen wrote:
>>Going by memory, Linux will generally be 1ms resolution (I might be
>>off by 10 there...), while Windows XP has about 64 ticks per second,
>>so .015625 resolution...
>
[snip script]
> if I run this on the Windows 2K box I'm sitting at right now, it sett
On 2005-12-07, Grant Edwards <[EMAIL PROTECTED]> wrote:
for f in range(10):
> ... print t()-t()
> ...
> -4.05311584473e-06
> -1.90734863281e-06
> -1.90734863281e-06
> -2.14576721191e-06
> -2.86102294922e-06
> -1.90734863281e-06
> -2.14576721191e-06
> -2.14576721191e-06
> -9.53674316406e-07
On 2005-12-07, Bengt Richter <[EMAIL PROTECTED]> wrote:
>>In my experience, time.time() on Linux has a resolution of
>>about 1us. The delta I get when I do
>>
>> print time.time()-time.time()
>>
>>is usually about 2-3us, but some of that is probably due to the
>>overhead involved.
>>
> Try
>
> >
On Wed, 07 Dec 2005 16:35:15 -, Grant Edwards <[EMAIL PROTECTED]> wrote:
>On 2005-12-07, Peter Hansen <[EMAIL PROTECTED]> wrote:
>
>> 2. If your system returns figures after the decimal point, it
>>probably has better resolution than one second (go figure).
>>Depending on what system i
On 2005-12-07, Fredrik Lundh <[EMAIL PROTECTED]> wrote:
>>> if I run this on the Windows 2K box I'm sitting at right now,
>>> it settles at 100 for time.time, and 1789772 for time.clock.
>>> on linux, I get 100 for time.clock instead, and 262144 for
>>> time.time.
>>
>> At least under Linux, I sus
Grant Edwards wrote:
> >> Going by memory, Linux will generally be 1ms resolution (I might be
> >> off by 10 there...), while Windows XP has about 64 ticks per second,
> >> so .015625 resolution...
> >
> > here's a silly little script that measures the difference between
> > two distinct return va
On 2005-12-07, Grant Edwards <[EMAIL PROTECTED]> wrote:
>> if I run this on the Windows 2K box I'm sitting at right now, it settles
>> at 100 for time.time, and 1789772 for time.clock. on linux, I get 100
>> for time.clock instead, and 262144 for time.time.
>
> At least under Linux, I suspect you
On 2005-12-07, Fredrik Lundh <[EMAIL PROTECTED]> wrote:
> Peter Hansen wrote:
>
>> Going by memory, Linux will generally be 1ms resolution (I might be
>> off by 10 there...), while Windows XP has about 64 ticks per second,
>> so .015625 resolution...
>
> here's a silly little script that measures t
On 2005-12-07, Peter Hansen <[EMAIL PROTECTED]> wrote:
> 2. If your system returns figures after the decimal point, it
>probably has better resolution than one second (go figure).
>Depending on what system it is, your best bet to determine
>why is to check the documentation for your sy
Peter Hansen wrote:
> Going by memory, Linux will generally be 1ms resolution (I might be
> off by 10 there...), while Windows XP has about 64 ticks per second,
> so .015625 resolution...
here's a silly little script that measures the difference between
two distinct return values, and reports the
Thanks to everyone for their e-mails. I am using
Fredrik's strptime/mktime solution to calculate my
elapsed time.
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malv wrote:
> "Note that even though the time is always returned as a floating point
> number, not all systems provide time with a better precision than 1
> second." says the doc.
> Can anything be said about precision if indeed your system returns
> figures after the decimal point?
A few things.
"Note that even though the time is always returned as a floating point
number, not all systems provide time with a better precision than 1
second." says the doc.
Can anything be said about precision if indeed your system returns
figures after the decimal point?
Thx.
malv
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http://mail.python.org
On Tue, 6 Dec 2005 12:36:55 -0800 (PST), Jean Johnson <[EMAIL PROTECTED]> wrote:
>Hello -
>
>I have a start and end time that is written using the
>following:
>
>time.strftime("%b %d %Y %H:%M:%S")
>
>How do I calculate the elapsed time?
>
>>> tf1 = time.strftime("%b %d %Y %H:%M:%S")
>>> tf1
Jean> I'm using an old version of python (2.1) and datetime isn't
Jean> available until Python 2.3. I can't upgrade my python.
There's a reference implementation of datetime written in Python:
http://svn.python.org/view/sandbox/trunk/datetime/
It may or may not work in 2.1. If you
Jean Johnson wrote:
> I have a start and end time that is written using the
> following:
>
> time.strftime("%b %d %Y %H:%M:%S")
>
> How do I calculate the elapsed time?
import time
FORMAT = "%b %d %Y %H:%M:%S"
t1 = time.strftime(FORMAT)
print t1
time.sleep(1)
t2 = time.strftime(FORMAT)
prin
I'm using an old version of python (2.1) and datetime
isn't available until Python 2.3. I can't upgrade my
python.
--- [EMAIL PROTECTED] wrote:
>
> Jean> How do I calculate the elapsed time?
>
> Where t1_s and t2_s reference time strings in the
> format you describe:
>
> import dateti
Jean> How do I calculate the elapsed time?
Where t1_s and t2_s reference time strings in the format you describe:
import datetime
import time
fmt = "%b %d %Y %H:%M:%S"
t1 = datetime.datetime(*time.strftime(t1_s, fmt)[:6])
t2 = datetime.datetime(*time.strftime(t2_s, fmt
Hello -
I have a start and end time that is written using the
following:
time.strftime("%b %d %Y %H:%M:%S")
How do I calculate the elapsed time?
JJ
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