From: stewart@... (Stewart Midwinter)
Date: 2002-07-19T07:10:25+09:00
Subject: newbie Q: parsing CSV file into 2D array

Sorry about the low level of this Q. I've ordered Hal Fulton's book
but it hasn't arrived yet... :-(

I'm trying to read in a series of records in a CSV file. Each record
has a number of fields. I then want to write out the records in a
paragraph form, if you will.  This requires that I create a 2D array.

The following code shows what I am trying to do; it also contains a
sample line from the input file, and a sample desired output file
excerpt.

so far, I am able to read in lines, and write out lines, but I'm not
getting a 2D array, I think.  I believe I might need to chomp! each
line into addition to split, but I'm not sure about this.  Any ideas? 
Thanks!

Please respond to stewart 'at' midwinter 'dot' ca


# format of input file lines:
#Wheel_Name,min_pwr,mid_pwd,max_pwr,fuel_min,fuel_mid,fuel_max,rpm_min,rpm_mid,rpm_max,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,Temp.,Power,,,
#parsing an input file, and writing reformatted data to output file
#FP-714,2307.741935,2942.370968,3577,9155.6,10712.7,12269.7,10000,12750,15500,-40,3577,-35,3539,-30,3496,-25,3450,-20,3400,-15,3345,-10,3296,-5,3231,0,3171,5,3085,10,2991,15,2886,20,2769,25,2631,30,2504,35,2386,40,2278,,,,,,,
#want to split input lines firstly into array elements: 2d array for
file, 1 array per line
#after array is established, split data into two arrays: 
# 1st array: for data points up to and including max_pwr
# 2nd array: for data pairs of temp and power
# then print out reformatted data into output file, like so:
#FP-107                                                 <--unit name
#23436    27973  32510                            <-- min, mid, max
pwr
#61800.92 70410  79018.836                     <-- min, mid, max fuel
#	4270   5337.5 6405                           <-- min, mid, max rpm
#-45     32510  32510  32510                     <-- a temp, and 3
power values (for 3 rpms)
#-10     32564  32564  32564	               <-- ditto
#0       32143  32143  32143
#35      23436  23436  23436
#repeat for next record from input file
  
ary = []
fh = File.open("c:\AB_fuel.csv","r");
out = File.open("c:\AB_fuel.out","w");
fh.each { |line|
        a = line.strip.split(',')
        ary << a
	out.puts line
}
# test print-out of one array element
puts ary[2]
fh.close; out.close;