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Posted by dennis.sprengers on 05/07/07 15:40
Wow, thanks! It works great. I will spend the next hour or so trying
to understand what code you wrote and why I still can't come up with
stuff solutions that :-)
On 7 mei, 17:32, ZeldorBlat <zeldorb...@gmail.com> wrote:
> On May 7, 11:05 am, dennis.spreng...@gmail.com wrote:
>
>
>
> > Consider the following multi-dimensional array:
> > ---------------------------
> > $arr = array(
> > array(3, 5, 7, 9),
> > array(2, 4, 6, 8),
> > array(1, 3, 5, 7)
> > );
>
> > function add_arrays($arr) {
> > for ($row = 0; $row < count($arr[0]); $row++) {
> > for ($column = 0; $column < count($arr[$column]); $column++) {
> > $totals[$row] = $totals[$row] + $arr[$column][$row];
> > }
> > }
> > print_r($totals);
>
> > }
>
> > add_arrays($arr);
> > ---------------------------
> > This returns the following array:
> > Array ( [0] => 6 [1] => 12 [2] => 18 [3] => 24 )
>
> > These are the totals of the array's in $arr: 6 (3 + 2 + 1, added all
> > first elements), 12 (5 + 4 + 3, added all second elements), etc. This
> > took me quite a portion of the day to construct ;) However, I would
> > like add_arrays to return a multidimensional array like this:
>
> > Array (
> > Array ( [0] => 3 [1] => 5 [2] => 7 [3] => 9 ) // 1st row
> > Array ( [0] => 5 [1] => 9 [2] => 13 [3] => 17 ) // 1st row + second
> > row (i.e. 5 = 3 + 2)
> > Array ( [0] => 6 [1] => 12 [2] => 18 [3] => 24 ) // 1st _ 2nd + 3rd
> > row (i.e. 6 = 3 + 2 + 1)
> > )
>
> > Could somebody please help me building a function that does just that?
> > Adding one row to the previous one and adding the result to the output
> > array? Any help would be greatly apprectiated!
>
> Here's one way. Obviously there are others, also.
>
> function add_arrays_cumulative($arr) {
> $out = array();
>
> for($i = 0; $i < count($arr); $i++) {
> if(!isset($out[$i]))
> $out[$i] = array();
>
> for($j = 0; $j < count($arr[$i]); $j++)
> $out[$i][$j] = $arr[$i][$j] + (isset($out[$i-1][$j]) ?
> $out[$i-1][$j] : 0);
> }
>
> return $out;
>
> }
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