[SciPy-user] Print number of significant digits ?

Nils Wagner nwagner@iam.uni-stuttgart...
Fri Jun 15 05:39:04 CDT 2007


Steve Schmerler wrote:
> Stef Mientki wrote:
>   
>> Joachim Dahl wrote:
>>     
>>> print "%3.2f" %pi
>>>       
>> thanks Joachim,
>>
>> but I didn't phrase my question accurate enough,
>> I not only want to print pi, but I want to print anything
>>
>> e.g. I now get:
>>   Model 1.0000000149 1.0 [ 1.00000001  1.00000001  3.00000001  
>> 4.00000001  5.00000001]
>>
>> but I want
>>   Model 1.00 1.0 [ 1.00  1.00  3.00  4.00  5.00]
>>
>> and as I use "print" as a quick and dirty intermediate result for 
>> everything,
>> I don't want to spell out each format statement.
>>
>>     
>
> Hmm I'm not aware of a built-in for doing this. A quick and dirty solution would be
>
> a = array([1,2,3,pi])
> fmt = "%3.2f "*len(a)
> fmt = fmt.strip()
>
> Then,
>
> In [28]: a
> Out[28]: array([ 1.        ,  2.        ,  3.        ,  3.14159265])
>
> In [29]: fmt %tuple([aa for aa in a])
> Out[29]: '1.00 2.00 3.00 3.14'
>
>
>   
You can use set_printoptions
set_printoptions(precision=None, threshold=None, edgeitems=None,
linewidth=None, suppress=None)
    Set options associated with printing.

    :Parameters:
        precision : int
            Number of digits of precision for floating point output
(default 8).
        threshold : int
            Total number of array elements which trigger summarization
            rather than full repr (default 1000).
        edgeitems : int
            Number of array items in summary at beginning and end of
            each dimension (default 3).
        linewidth : int
            The number of characters per line for the purpose of inserting
            line breaks (default 75).
        suppress : bool
            Whether or not suppress printing of small floating point values
            using scientific notation (default False).

>>> from scipy import *
>>> set_printoptions(precision=2)
>>> print pi
3.14159265359
>>> print array([pi])
[ 3.14]

Nils

 


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