[SciPy-user] Again on Double Precision

Lorenzo Isella lorenzo.isella@gmail....
Sat Sep 1 07:58:10 CDT 2007


Dear All,
I know this is related to a thread which had been going on for a while, 
but I am about to publish some results of a simulation making use of 
integrate.odeint and I would like to be sure I have not misunderstood 
anything fundamental.
I was using all my arrays and functions to be dealt with by 
integrate.odeint without ever bothering too much about the details, i.e. 
I never specified explicitly the  "type"  of arrays I was using..
I assumed that  integrate.odeint  was a thin layer to some Fortran 
routine and it would automatically convert to Fortran double-precision 
all the due quantities.
Is this what is happening really? I actually have no reason to think 
that my results are somehow inaccurate, but a you never know.
I was getting worried after looking at:
http://www.scipy.org/Cookbook/BuildingArrays

Apologies if this is too basic for the forum, but in Fortran I always  
used double precision as a standard and  in R all the  numbers/arrays 
are  stored as double precision  objects and you do not have to worry 
(practically the only languages I use apart from Python). In the end of 
the day, double precision is a specific case of floating point numbers 
and I wonder if, when working with the default floating arrays in SciPy, 
I attain the same accuracy  I would get  with double-precision  Fortran 
arrays.
Many thanks for any enlightening  comment.

Lorenzo


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