round numbers in an array without importing Numeric or Math?

[Lance Hoffmeyer]

Is there an easy way to round numbers in an array?

I have
Test = [1.1,2.2,3.7]

and want to round so the values are

print Test [1,2,4]


Lance

[Alexander Schmolck]

Re: round numbers in an array without importing Numeric or Math?

Lance Hoffmeyer <lance@augustma il.com> writes:
[color=blue]
> Is there an easy way to round numbers in an array?
>
> I have
> Test = [1.1,2.2,3.7]
>
> and want to round so the values are
>
> print Test [1,2,4][/color]

[int(x+0.5) for x in Test]

'as

[Lance Hoffmeyer]

Re: round numbers in an array without importing Numeric or Math?

May have a complicating issue with the array? Have
the numbers have been interpreted as strings? I have
been pulling them from a Word doc using regex's

print Test
[u'9.0', u'58.6', u'97.8', u'10.0', u'9.6', u'28.1']


Lance


Alexander Schmolck wrote:[color=blue]
> Lance Hoffmeyer <lance@augustma il.com> writes:
>[color=green]
>> Is there an easy way to round numbers in an array?
>>
>> I have
>> Test = [1.1,2.2,3.7]
>>
>> and want to round so the values are
>>
>> print Test [1,2,4][/color]
>
> [int(x+0.5) for x in Test]
>
> 'as[/color]

[Dan Sommers]

Re: round numbers in an array without importing Numeric or Math?

On Tue, 16 May 2006 13:41:37 -0500,
Lance Hoffmeyer <lance@augustma il.com> wrote:
[color=blue]
> May have a complicating issue with the array? Have
> the numbers have been interpreted as strings? I have
> been pulling them from a Word doc using regex's[/color]
[color=blue]
> print Test
> [u'9.0', u'58.6', u'97.8', u'10.0', u'9.6', u'28.1'][/color]

Then you'll have to convert your strings to floats first:

[int(float(x)+0. 5) for x in Test]

HTH,
Dan

--
Dan Sommers
<http://www.tombstoneze ro.net/dan/>
"I wish people would die in alphabetical order." -- My wife, the genealogist

[skip@pobox.com]

Re: round numbers in an array without importing Numeric or Math?


Lance> May have a complicating issue with the array? Have the numbers
Lance> have been interpreted as strings? I have been pulling them from
Lance> a Word doc using regex's

[int(float(x)+0. 5) for x in Test]

S

[Lance Hoffmeyer]

Re: round numbers in an array without importing Numeric or Math?- SOLVED, sort of

The array comes out as unicode. This is probably because I am grabbing the numbers
from a Word Doc using regex's.

So, before rounding I perform the following:
# Convert to String
Topamax = [str(x) for x in Topamax]
# Convert to floating
Topamax = [float(x) for x in Topamax]
# Finally, round the number
Topamax= [(x+0.5) for x in Topamax]

Is there a shorter way?

Lance



Lance Hoffmeyer wrote:[color=blue]
> Is there an easy way to round numbers in an array?
>
> I have
> Test = [1.1,2.2,3.7]
>
> and want to round so the values are
>
> print Test [1,2,4]
>
>
> Lance[/color]

[Paul McGuire]

Re: round numbers in an array without importing Numeric or Math? - SOLVED, sort of

"Lance Hoffmeyer" <lance@augustma il.com> wrote in message
news:446a2032$0 $61167$ae4e5890 @news.nationwid e.net...[color=blue]
> The array comes out as unicode. This is probably because I am grabbing[/color]
the numbers[color=blue]
> from a Word Doc using regex's.
>
> So, before rounding I perform the following:
> # Convert to String
> Topamax = [str(x) for x in Topamax]
> # Convert to floating
> Topamax = [float(x) for x in Topamax]
> # Finally, round the number
> Topamax= [(x+0.5) for x in Topamax]
>
> Is there a shorter way?
>
> Lance
>
>
>
> Lance Hoffmeyer wrote:[color=green]
> > Is there an easy way to round numbers in an array?
> >
> > I have
> > Test = [1.1,2.2,3.7]
> >
> > and want to round so the values are
> >
> > print Test [1,2,4]
> >
> >
> > Lance[/color][/color]

(c.l.py people don't cotton to top-posting - when in Rome...)

# Convert to String, convert to floating, and finally, round the number all
in one swell foop
Topamax= [int(float(str(x ))+0.5) for x in Topamax]

-- Paul

[Paul McGuire]

Re: round numbers in an array without importing Numeric or Math? - SOLVED, sort of

"Lance Hoffmeyer" <lance@augustma il.com> wrote in message
news:446a2032$0 $61167$ae4e5890 @news.nationwid e.net...[color=blue]
> The array comes out as unicode. This is probably because I am grabbing[/color]
the numbers[color=blue]
> from a Word Doc using regex's.
>
> So, before rounding I perform the following:
> # Convert to String
> Topamax = [str(x) for x in Topamax]
> # Convert to floating
> Topamax = [float(x) for x in Topamax]
> # Finally, round the number
> Topamax= [(x+0.5) for x in Topamax]
>
> Is there a shorter way?
>
> Lance
>
>[/color]
.... or if you prefer the functional approach (using map)...

roundToInt = lambda z : int(z+0.5)
Topamax = map( roundToInt, map( float, map(str, Topamax) ) )

(Python also has a built-in round() function, but this returns floats, not
ints - if that is okay, then just delete the lambda definition, and replace
roundToInt with round.)

-- Paul

[Scott David Daniels]

Re: round numbers in an array without importing Numeric or Math?- SOLVED, sort of

Paul McGuire wrote:[color=blue]
> ... or if you prefer the functional approach (using map)...
>
> roundToInt = lambda z : int(z+0.5)
> Topamax = map( roundToInt, map( float, map(str, Topamax) ) )[/color]

Somehow, the list comprehension looks simpler and clearer to me:

Topamax = [int(float(uni) + .5) for uni in Topamax]

I really dislike lines like:
roundToInt = lambda z : int(z+0.5)

You've already chosen a name, but you'd rather write in the lisp style.

def roundToInt(z):r eturn int(z+0.5)

takes all of _one_ more character.

I also don't understand why you convert to string from unicode in:

... map(str, Topamax) ) )

float works on all string types (including unicode), and will accept
some non-ASCII digit values.

--
-Scott David Daniels
scott.daniels@a cm.org

[Bernhard Herzog]

Re: round numbers in an array without importing Numeric or Math? -SOLVED, sort of

"Paul McGuire" <ptmcg@austin.r r._bogus_.com> writes:
[color=blue]
> ... or if you prefer the functional approach (using map)...
>
> roundToInt = lambda z : int(z+0.5)
> Topamax = map( roundToInt, map( float, map(str, Topamax) ) )
>
> (Python also has a built-in round() function, but this returns floats, not
> ints - if that is okay, then just delete the lambda definition, and replace
> roundToInt with round.)[/color]

Your roundToInt behaves differently from round for negative numbers:
[color=blue][color=green][color=darkred]
>>> roundToInt(-0.6)[/color][/color][/color]
0[color=blue][color=green][color=darkred]
>>> int(round(-0.6))[/color][/color][/color]
-1

Bernhard

--
Intevation GmbH http://intevation.de/
Skencil http://skencil.org/
Thuban http://thuban.intevation.org/