[SOLVED] Sum array values in pairs of 4

[SOLVED] Sum array values in pairs of 4 26 Sep 2012 22:29 #4047

dyvel
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Hi

I have a problem that I hope someone can help me a bit with.

foreach ($mortgages as $mortgage_item) {
			$responseArray[$f] = $mortgage_item['mortgage'];
			$f++;
		}

is an array that generates a large array of values, e.g. 60 keys. I need to sum the values in bundles of 4, creating a new array with 15 keys, where key 0 contains the sum of the original array's key 0,1,2,3 - key 1 contains the sum of 4,5,6,7 etc.

But I can't figure this one out, so I hope someone here can help me a bit :-)

Thanks

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Last edit: by dyvel.

Re: Sum array values in pairs of 4 27 Sep 2012 06:12 #4049

JoomGuy
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Hi Dyvel,

There are a few ways you could do this...

If the array is always going to be a fixed value - 60 as you said - in my opinion, the easiest option would be to set your $f = 1 before you enter your foreach loop, begin building your new array of sums, iterating over it in the loop until $f = 4, then reset $f = 1.

This way, you should get what your after.

Does that make sense?

You may need to check that your array is divisible by 4 before you begin depending on what you're desired results are too.

Hope it helps,

Gez

Need help with your Cook/Joomla Project? . PM me to find out what I can help with. NO time wasters please!!!

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Re: Sum array values in pairs of 4 27 Sep 2012 08:12 #4051

dyvel Topic Author Offline Elite Member Posts: 200 Thank you received: 11	Hi Thank you for your reply and time. It is not a fixed value, and based on how many years a loan is running. The value 4 could also be 2 or 12
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Re: Sum array values in pairs of 4 27 Sep 2012 09:14 #4055

dyvel Topic Author Offline Elite Member Posts: 200 Thank you received: 11	This is giving me to much grey hair
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Re: Sum array values in pairs of 4 27 Sep 2012 09:21 #4057

admin Offline Administrator Chef Posts: 3711 Thank you received: 986	It reminds me the mathematicals problems at school. Once I have a bit of time I want to do it for fun. It is a long time I havn't done mathematics in programmation. I suddenly feel nostalgic of my first 3D engine under Qbasic. lol. Coding is now a piece of cake
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Re: Sum array values in pairs of 4 27 Sep 2012 09:25 #4058

dyvel
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I'm getting there... array_chunk seems to be the road to follow :-)

$responseArray = array();
		
		$f = 0;		
	
		foreach ($mortgages as $mortgage_item) {
			
			$responseArray[$f] = $mortgage_item['mortgage'];
			
			$f++;
		}
		
		return array_chunk($responseArray,$payment_frequency);

is giving me a multidimensional array like

Array
(
    [0] => Array
        (
            [0] => 10850
            [1] => 10850
            [2] => 10850
            [3] => 10850
        )

    [1] => Array
        (
            [0] => 10850
            [1] => 10850
            [2] => 10850
            [3] => 10850
        )
}

Now I "just" need to sum the values

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Re: Sum array values in pairs of 4 27 Sep 2012 09:39 #4060

admin
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Hum, not really advanced with that.
I do not think this function array_chunk is usefull for you.

I would have say, a double loop.

Algorithm :

NbCalculations = NbMortgages - frequency
Values = [];
for(i=0, i < count(NbCalculations), i++)
  Sum = 0
  for(j = 0, j < frequency, j++)
      Sum += Mortgages[i + j];
  endfor

  Values[i] = Sum
endfor

The first loop is sliding the first index (0, 1, 2)
The second loop is summing the values after it.

I am not sure if I understood well.

Coding is now a piece of cake

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Last edit: by admin.

Re: Sum array values in pairs of 4 27 Sep 2012 09:39 #4061

dyvel
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I did it

		$responseArray = array();
		$arrayChunk = array();
		$mergeArray = array();
		
		$f = 0;		
	
		foreach ($mortgages as $mortgage_item) {
			
			$responseArray[$f] = $mortgage_item['mortgage'];
			
			$f++;
		}
		
		$arrayChunk = array_chunk($responseArray,$payment_frequency);
		
		for ( $i = 0 , $n = count($arrayChunk) ; $i < $n ; $i++ ) :
			 
			 $mergeArray[$i] = array_sum($arrayChunk[$i]);	
			 
		endfor;
		
		return $mergeArray;

There might be a better solution to it, but it works

It returns an array like

Array
(
    [0] => 43400
    [1] => 43400
    [2] => 43400
    [3] => 43400
    [4] => 43400
    [5] => 132177.28
    [6] => 132177.28
    [7] => 132177.28
    [8] => 132177.28
    [9] => 132177.28
    [10] => 132177.28
    [11] => 132177.28
    [12] => 132177.28
    [13] => 132177.28
    [14] => 132177.43
)

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Last edit: by dyvel.

Re: Sum array values in pairs of 4 27 Sep 2012 09:42 #4062

dyvel
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admin wrote: Hum, not really advanced with that.
I do not think this function array_chunk is usefull for you.

I would have say, a double loop.

Algorithm :
NbCalculations = NbMortgages - frequency
Values = [];
for(i=0, i < count(NbCalculations), i++)
  Sum = 0
  for(j = 0, j < frequency, j++)
      Sum += Mortgages[i + j];
  endfor

  Values[i] = Sum
endfor
The first loop is sliding the first index (0, 1, 2)
The second loop is summing the values after it.

I am not sure if I understood well.

This looks like a more elegant solution than what I could come up with... will try if I can get it to work

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Re: Sum array values in pairs of 4 27 Sep 2012 09:53 #4063

admin Offline Administrator Chef Posts: 3711 Thank you received: 986	After, I read again, and I think it is not giving the result you want. If you want to jump every 'frequency' records, so change in : NbCalculations = (ceil)(NbMortgages / frequency) and : Sum += Mortgages[ifrequency + j]; I think... Good luck Coding is now a piece of cake* The following user(s) said Thank You: dyvel
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Re: Sum array values in pairs of 4 27 Sep 2012 12:21 #4074

BTB300
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You have 15 variables in the array but you need to add in multiples of 4 that means you need to move to the next record when you have read the 15th value double loop is needed
below in the format record-arrayposition 1-2 = record 1 position2
[1-1 to 1-4]
[1-5 to 1-8]
[1-9 to 1-12]
[1-13 to 1-15] plus [2-1]

[2-2 to 2-5]
[2-6 to 2-9]
[2-10 to 2-13]
[2-14 to 2-15] plus [3-1 to 3-2]

Sorry looked at what you needed again and was off track with the above

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Last edit: by BTB300.

Re: Sum array values in pairs of 4 27 Sep 2012 12:23 #4076

dyvel Topic Author Offline Elite Member Posts: 200 Thank you received: 11	Thanks, but as you can see from my previous post, I got it solved
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Re: Sum array values in pairs of 4 27 Sep 2012 12:27 #4077

admin Offline Administrator Chef Posts: 3711 Thank you received: 986	give me 5 i will construct for you MDR !! Too late... Coding is now a piece of cake
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Re: Sum array values in pairs of 4 27 Sep 2012 13:50 #4094

BTB300 Offline Moderator Posts: 415 Thank you received: 132	To Late its been a while since i did something like that
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