I have a variable number of vextors of variable length. I needt to put them into a rectangular matrix with as many columns as there are vectors and rows which contain all combinations of vector cell entries. For example, given the three vectors:

[a,b]

[c,d,e]

[f,g]

i need a matrix with 3 columns and 12 rows:

a c f

a c g

a d f

a d g

a e f

a e g

b c f

etc to…

b e g

Thanks for any help

Tony

# putting vectors into matrix

Loops are your friend:

```
$m1 = array("a", "b");
$m2 = array("c", "d", "e");
$m3 = array("f", "g");
$output = array();
$x = 0;
for ($i = 0; $i < count($m1); $i++) {
$first = $m1[$i];
for ($j = 0; $j < count($m2); $j++) {
$second = $m2[$i];
for ($k = 0; $k < count($m3); $k++) {
$third = $m3[$i];
$output[$x++] = array($first, $second, $third);
}
}
}
```

Thanks Zyppora, but the number of vectors is variable, so you can’t use $first, $second etc. However, I’ve solved it, painstakingly, by looking at the number of times each cell is repeated in a column, and the number of cycles of cell entries.

Tony