Like a matrix

[Yazar Yolait]

I have a string of numbers in a file like so:
0 3 23.3 352 45 4
4 45 23 54 4 5.4 .6

I need to average them horizontally and vertically. Horizontally is easy
since I'm reading one line at a time, but how can I do it vertically like 0
and 4, 3 and 45, etc.
I was thinking of a dictionary but how do you add entries to a dictionary,
you can't can you? Like I would add 0 to a dictionary that holds the 0th
column. And then when I get to line 2, I would add 4 to the dictionary
which has the 0th column data.

[Erik Max Francis]

Yazar Yolait wrote:

I have a string of numbers in a file like so:
0 3 23.3 352 45 4
4 45 23 54 4 5.4 .6

I need to average them horizontally and vertically. Horizontally is
easy
since I'm reading one line at a time, but how can I do it vertically
like 0
and 4, 3 and 45, etc.
Why not read it into a list of lists, and then iterate both ways?
I was thinking of a dictionary but how do you add entries to a
dictionary,
you can't can you?

Sure you can:

d = {}
d[0] = 'zero'
d {0: 'zero'} d[1] = 'one'
d {0: 'zero', 1: 'one'} d[10] = {'a': 1, 'b': 2, 'c': 3}
d

{0: 'zero', 1: 'one', 10: {'a': 1, 'c': 3, 'b': 2}}

--
Erik Max Francis && ma*@alcyone.com && http://www.alcyone.com/max/
__ San Jose, CA, USA && 37 20 N 121 53 W && &tSftDotIotE
/ \ The price of eternal vigilance is indifference.
\__/ Marshall McLuhan

[Peter Otten]

Yazar Yolait wrote:

I have a string of numbers in a file like so:
0 3 23.3 352 45 4
4 45 23 54 4 5.4 .6

I need to average them horizontally and vertically. Horizontally is easy
since I'm reading one line at a time, but how can I do it vertically like
0 and 4, 3 and 45, etc.
I was thinking of a dictionary but how do you add entries to a dictionary,
you can't can you? Like I would add 0 to a dictionary that holds the 0th
column. And then when I get to line 2, I would add 4 to the dictionary
which has the 0th column data.

from __future__ import division
def avg(alist): return sum(alist)/len(alist) .... u = [1,2,3]
v = [3,2,1]
avg(u) 2.0

So that was the easy part. Now let's create the columns:
m, n, o = zip(u, v)
m (1, 3) n (2, 2) avg(o) 2.0

So that wasn't particular hard, now you see it :-)
zip() returns tuples instead of lists, but as you see above that does no
harm.

Peter

[ryan scott]

Peter Otten wrote:

Yazar Yolait wrote:

I have a string of numbers in a file like so:
0 3 23.3 352 45 4
4 45 23 54 4 5.4 .6

I need to average them horizontally and vertically. Horizontally is easy
since I'm reading one line at a time, but how can I do it vertically like
0 and 4, 3 and 45, etc.
I was thinking of a dictionary but how do you add entries to a dictionary,
you can't can you? Like I would add 0 to a dictionary that holds the 0th
column. And then when I get to line 2, I would add 4 to the dictionary
which has the 0th column data.

from __future__ import division
def avg(alist): return sum(alist)/len(alist)
...
u = [1,2,3]
v = [3,2,1]
avg(u)
2.0

So that was the easy part. Now let's create the columns:

m, n, o = zip(u, v)
m
(1, 3)
n
(2, 2)
avg(o)
2.0
So that wasn't particular hard, now you see it :-)
zip() returns tuples instead of lists, but as you see above that does no
harm.

Peter

As an addition to this post, you could use avg in map to return a list
of your averages.
map(avg, zip(u,v))

[2.0, 2.0, 2.0]
Ryan