On Sunday, 22 May 2016 17:26:51 UTC+10, Sayth Renshaw wrote:
> I am doing a passage in a book that was written for python 2 i am writing
> everything in 3.
>
> This is the author Ivan Idris code to show time difference between python and
> numpy arrays. The only edit I made was to fix the print statements.
>
> #!/usr/bin/env/python
>
> import sys
> from datetime import datetime
> import numpy as np
>
> """
> This program demonstrates vector addition the Python way.
> Run from the command line as follows
>
> python vectorsum.py n
>
> where n is an integer that specifies the size of the vectors.
>
> The first vector to be added contains the squares of 0 up to n.
> The second vector contains the cubes of 0 up to n.
> The program prints the last 2 elements of the sum and the elapsed time.
> """
>
> def numpysum(n):
> a = np.arange(n) ** 2
> b = np.arange(n) ** 3
> c = a + b
>
> return c
>
> def pythonsum(n):
> a = range(n)
> b = range(n)
> c = []
>
> for i in range(len(a)):
> a[i] = i ** 2
> b[i] = i ** 3
> c.append(a[i] + b[i])
>
> return c
>
> size = int(sys.argv[1])
>
> start = datetime.now()
> c = pythonsum(size)
> delta = datetime.now() - start
> print("The last 2 elements of the sum", c[-2:])
> print("PythonSum elapsed time in microseconds", delta.microseconds)
>
> start = datetime.now()
> c = numpysum(size)
> delta = datetime.now() - start
> print("The last 2 elements of the sum", c[-2:])
> print("NumPySum elapsed time in microseconds", delta.microseconds)
>
>
> However when I run this I get a valuerror. So either something has changed
> with int or datetime I cannot google a consistent answer.
>
>
> ---------------------------------------------------------------------------
> ValueError Traceback (most recent call last)
> <ipython-input-8-a54a878f293d> in <module>()
> 37 return c
> 38
> ---> 39 size = int(sys.argv[1])
> 40
> 41 start = datetime.now()
>
> ValueError: invalid literal for int() with base 10: '-f'
>
> Had this before?
>
> Sayth
Thank you all, I was way wrong. I was invoking it from within ipython notebook
which I don't usually use.
Thanks'
Sayth
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