Mathematica 7 compares to other languages
Paul Rudin
paul.nospam at rudin.co.uk
Thu Dec 11 06:40:45 CET 2008
"Dotan Cohen" <dotancohen at gmail.com> writes:
> 2008/12/10 <w_a_x_man at yahoo.com>:
>> On Dec 5, 9:51 am, Xah Lee <xah... at gmail.com> wrote:
>>>
>>> For those of you who don't know linear algebra but knows coding, this
>>> means, we want a function whose input is a list of 3 elements say
>>> {x,y,z}, and output is also a list of 3 elements, say {a,b,c}, with
>>> the condition that
>>>
>>> a = x/Sqrt[x^2+y^2+z^2]
>>> b = y/Sqrt[x^2+y^2+z^2]
>>> c = z/Sqrt[x^2+y^2+z^2]
>>
>>>
>>> In lisp, python, perl, etc, you'll have 10 or so lines. In C or Java,
>>> you'll have 50 or hundreds lines.
>>
>> Ruby:
>>
>> def norm a
>> s = Math.sqrt(a.map{|x|x*x}.inject{|x,y|x+y})
>> a.map{|x| x/s}
>> end
>
> If someone doesn't counter with a Python one-liner then I'm going to
> port that to brainfuck.
from numpy.linalg import norm
:)
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