inshu chauhan <insidesh...@gmail.com> wrote:
>
>but i want to calculate it for every 3 points not the whole data, but
>instead of giving me centre for every 3 data the prog is printing the
>centre 3 times...
>
>def main (data):
> j = 0
> for i in data[:3]:
> while j != 3:
> centre = CalcCentre(data)
> j += 1
> print centre
This loop doesn't do what you think it does. Think about the problem you
have to solve. You have a set of data. You want to operate on the whole
set, 3 points at a time. What this loop does is grab the first three
points (only), then calculates the center on the entire list three times.
You want something like:
# As long as there is data in the list:
while data:
# Split the list into two parts: first 3 and the rest.
first3, data = data[3:],data[3:]
# Operate on the first three.
print CalcCenter( first3 )
To make it a little more resilient, you might make sure that len(data) is a
multiple of 3, or at least stop when it is shorter than 3.
To be more clever, you can write a function that returns 3 at a time:
def N_at_a_time( iter, n ):
while len(iter) >= n:
yield iter[:n]
iter = iter[n:]
Now you can do this:
def main(data):
for first3 in N_at_a_time(data, 3):
print CalcCenter(first3)
--
Tim Roberts, t...@probo.com
Providenza & Boekelheide, Inc.
--
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