From: Todd Benson <caduceass@...>
Date: 2012-11-17T08:54:32+09:00
Subject: Re: Accumulate the value of an array if this is repeated

On Fri, Nov 16, 2012 at 12:09 PM,  <sto.mar@web.de> wrote:
> Am 16.11.2012 17:51, schrieb Joao Silva:
>
>> Hi All.
>>
>> I have an arrangement with a series of numbers and a string. What I'm
>> trying to make is that when I read an array value compare it to the
>> value of the string and accumulate certain portion of the string if this
>> is repeated.
>>
>> I have the array "numbers":
>>
>> http://dpaste.com/832132/
>>
>> and I have the string "amounts"
>>
>> http://dpaste.com/832133/
>>
>> What I'm trying to make is that if I find a number of array "numbers" in
>> the string "amounts", I return the "amount" contained in the string, but
>> if the number of array "numbers" is repeated string "amounts" I returns
>> the sum of the values contained in the string, then place it in
>> another array.
>>
>> Here is the code:
>>
>> ######################################################################
>>
>> http://dpaste.com/832134/
>>
>> ########################################################################
>>
>> for example if you found the number "20222999" contained in the array
>> "numbers" in the string "amounts" which returns the sum of all amounts
>> associated with that number, in this case would be:
>>
>>
>> sum = 205.15 + 110.00
>> sum = 315.15
>>
>> and value "sum" is assigned to a new array.
>>
>> Thanks.
>
>
> Please shorten your examples and include the code in the E-Mail.
> Also describe more explicitly what your specific problem/question is.
>
> As you already found out, your code can not work...
> You will have to read up heavily on the basics and you should
> also make it a habit to use irb for playing around with the different
> parts of your code.
>
> E.g.:
>
>   numbers=[
>   20222999
>   20777444
>   30222999
>   ...
>   ]
>
> This is not even an array and gives a syntax error.
> You need to separate array elements by comma.
>
> Or:
>
>   numbers.include? ("amounts[0..7]")
>
> This searches for the exact string "amounts[0..7]",
> which certainly can not be found in your data.
>
> You mean:
>
>   numbers.include?(amounts[0..7])
>
> which doesn't work either because the numbers array will
> probably contain integers and amounts[0..7] is a string.
>
> 1.9.3p194 :001 > [12345, 23456].include?("12345")
>  => false
> 1.9.3p194 :002 > [12345, 23456].include?(12345)
>  => true
>
> and so on...
>
>
> One approach (there are many) to solve your problem would be:
>
> - split your amounts string into an array of single lines
> - go through the array, split each entry into number and amount,
>   and build a hash with the numbers as keys and
>   an array with all the amounts for that number as value
> - then go through your hash and add the values up

Something like this? I'm making a hash from the second and running
through the selected numbers against the dictionary (hash) after...

numbers_str = "1
2
3
7
5"
amounts_str = "1 22.4
3 46.2
9 2.0
1 15.15
2 14.0
5 2.4
1 1.5
3 17.25"

# just to get them into array form converted
numbers = numbers_str.split.map &.to_i
amounts = amounts_str.split("\n").map {|e| e.split.map &:to_f}

# go through amounts filling a hash
h = Hash.new(0)
amounts.each {|e| h[e[0].to_i] += e[1]}

# print all sums
p h

# print sums for select numbers
numbers.each {|n| p "#{n}: #{h[n]}"}