How to increment array elements with loop?

[deko]

I need to populate a file with past unix time stamps over a period of time
specified by the user. The time stamps should be evenly spaced, based on
user-defined parameters.

My question is: How do I add an element to an array, then increment it and
loop so that each element builds on the previous element just added?

Here's a first crack at it:

<?php
$data_file = 'timedata.txt';
$avdaily = 25 //user-defined
$total_count = (183 * $avdaily) //time period = six months
$interval = (3600*24)/$avdaily //evenly spaced intervals
$first_time = time() - (3600*24*183)
$next_time = ($first_time + $interval)
//add $next_time to $data_array -- here's where I'm lost
$next_time = ($next_time + $interval)
//add $next_time to $data_array
//loop until $data_array has $total_count elements
//write $data_array to $data_file
//newest time should be last line in file
?>

This output should be a file that has a
series of unix time stamps incremented
by the amount of $interval. The below output
example increments by 10 seconds each iteration.

1081111110
1081111120
1081111130
1081111140
1081111150
1081111160
1081111170
1081111180
1081111190

Any help is appreciated! Thanks.

[Chris Hope]

deko wrote:

I need to populate a file with past unix time stamps over a period of time
specified by the user. The time stamps should be evenly spaced, based on
user-defined parameters.

My question is: How do I add an element to an array, then increment it
and loop so that each element builds on the previous element just added?

Here's a first crack at it:

<?php
$data_file = 'timedata.txt';
$avdaily = 25 //user-defined
$total_count = (183 * $avdaily) //time period = six months
$interval = (3600*24)/$avdaily //evenly spaced intervals
$first_time = time() - (3600*24*183)
$next_time = ($first_time + $interval)
//add $next_time to $data_array -- here's where I'm lost
$next_time = ($next_time + $interval)
//add $next_time to $data_array
//loop until $data_array has $total_count elements
//write $data_array to $data_file
//newest time should be last line in file
?>

This output should be a file that has a
series of unix time stamps incremented
by the amount of $interval. The below output
example increments by 10 seconds each iteration.

1081111110
1081111120
1081111130
1081111140
1081111150
1081111160
1081111170
1081111180
1081111190

Any help is appreciated! Thanks.

How about something like this?

function build_timestamp_array($start_timestamp, $interval, $number) {

$array = array();
for($i = 0; $i < $number; $i++) {
$array[] = $start_timestamp + $interval * $i;
}
return $array;

}
--
Chris Hope - The Electric Toolbox - http://www.electrictoolbox.com/

[deko]

> How about something like this?

function build_timestamp_array($start_timestamp, $interval, $number) {

$array = array();
for($i = 0; $i < $number; $i++) {
$array[] = $start_timestamp + $interval * $i;
}
return $array;

}

I'm somewhat of a rookie with functions - this is what I think it would look
like in pseudo code:

<?php
$data_file = 'timedata.txt';
$avdaily = 25 //user-defined
$total_count = (183 * $avdaily) //time period = six months
$interval = (3600*24)/$avdaily //evenly spaced intervals
$first_time = time() - (3600*24*183)
//$next_time = ($first_time + $interval)

for($i = 0; $i < $total_count; $i++) {
$timestamp_array[] = $first_time + ($interval * $i);
}

???

//newest time should be last line in file
?>

This output should be a file that has a
series of unix time stamps incremented
by the amount of $interval. The below output
example increments by 10 seconds each iteration.

1081111110
1081111120
1081111130
1081111140
1081111150
1081111160
1081111170
1081111180