From: Michael Sc <michael.schatzow@...>
Date: 2007-02-12T21:49:52+09:00
Subject: Re: embedding if statements in upto function.(newbie questio

Thanks Brian, I appreciate the help.


I changed the code and ran it again.
0.upto( a.size-2 ) {|i|
  if (a[i][2]==a[i+1][2] and a[i][0]==a[i+1][0]) then
    puts ( (a[i+1][3] - a[i][3]) / a[i][3] * 100 )
else puts 0
end}
With this I get an error on the 3rd line of undefined method(-) for ".08 
#(the first number)#":String(NoMethodError)Print was able to do the 
calculation without the if statements. I think I misunderstood how 
output in FasterCSV processes files.  basically, I sorted a csv file and 
I was trying to do some simple math on that file.

Basically here is what I need to do.  I have very large csv files and I 
wanted to create percentage changes.  Should I try to change a to an 
array?

I have a file that looks like this
x1  date1  y1 #
x1  date2  y1 #
...
x1  date1  y2 #
x1  date2  y2 #
...
x2  date1  y1 #
x2  date2  y1 #

I just want to returns only if columns 1 and 3 equal the next point in 
the column.
Thanks again.
Michael
Brian Candler wrote:
> On Mon, Feb 12, 2007 at 08:05:01PM +0900, Michael Sc wrote:
>> else print 0
>> end}
> 
> Why don't you give some sample data, and show what happens when you run 
> it.
> Preferably make a small, standalone program which demonstrates the 
> problem.
> Do you get an exception raised? A wrong result?
> 

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