<?php
/* -----------------------------------------------------------------------------------
This module contains two merge functions, one for date and one for country arrays
plus ancillary functions.
(c) Copyright 2004 Arthur Sale, University of Tasmania
----------------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------------
This function computes an integer datestamp to a month resolution.
(c) Copyright 2004 Arthur Sale, University of Tasmania
Parameters:
An array and an index into it
Returns:
Result: the datestamp
------------------------------------------------------------------------------ */
function datestamp(&$x, $j)
// reference parameter for efficiency, not changed
// invalid dates return zero, ie earlier than any possible date.
{
if ($j < count($x)) {
// $mo is in {0..11}
$mo = (int) strpos('JanFebMarAprMayJunJulAugSepOctNovDec', $x[$j]["month"])/3;
return (int) $x[$j]["year"]*12 + $mo;
} else {
return 0;
}
}
/* ------------------------------------------------------------------------------
This function merges two date arrays, to produce a single consolidated array.
Note that either of the two arrays might be missing a view for a month or more.
Precondition: both arrays are ordered in descending order of date (latest first)
as is the result array.
(c) Copyright 2004 Arthur Sale, University of Tasmania
Parameters:
Two date-ordered arrays: abstracts and downloads
Returns:
Result: merged array also ordered by date
NJS 2006-01-18: Added count of distinct countries.
------------------------------------------------------------------------------ */
function merge_dates(&$aa, &$ad)
// reference parameters for efficiency, not changed
{
$merged = array();
// start of all arrays
$i = 0;
$indexa = 0;
$indexd = 0;
// set up the rest of the loop invariant
$datea = datestamp($aa,0);
$dated = datestamp($ad,0);
// $datei is initialized to the most recent date for which an access is recorded
$datei = max($datea, $dated);
while (($datea + $dated) != 0) {
// Loop invariant: All elements prior to $indexa in $aa and $indexd in $ad
// have been transferred to $merged (ie all dates *after* $datei)
// Progress: $date1 is decremented by 1 (ie one month *earlier*)
// Termination: No more elements, signalled by both datestamps == 0.
if (($datea == $datei) and ($dated == $datei)) {
// Both are valid and equal to the current date being displayed, the majority case
$merged[$i] = array(
"downloads" => $ad[$indexd]["count"],
"dcountries" => $ad[$indexd]["countries"],
"abstracts" => $aa[$indexa]["count"],
"acountries" => $aa[$indexa]["countries"],
"month" => $ad[$indexd]["month"], // same value as aa
"year" => $ad[$indexd]["year"] // same value as aa
);
$indexa++; $indexd++;
$datea = datestamp($aa,$indexa);
$dated = datestamp($ad,$indexd);
} elseif ($datea == $datei) {
// aa (but not ad) is equal to the current date being displayed
$merged[$i] = array(
"downloads" => 0,
"dcountries" => 0,
"abstracts" => $aa[$indexa]["count"],
"acountries" => $aa[$indexa]["countries"],
"month" => $aa[$indexa]["month"],
"year" => $aa[$indexa]["year"]
);
$indexa++;
$datea = datestamp($aa,$indexa);
} elseif ($dated == $datei) {
// ad (but not aa) is equal to the current date being displayed
$merged[$i] = array(
"downloads" => $ad[$indexd]["count"],
"dcountries" => $ad[$indexd]["countries"],
"abstracts" => 0,
"acountries" => 0,
"month" => $ad[$indexd]["month"],
"year" => $ad[$indexd]["year"]
);
$indexd++;
$dated = datestamp($ad,$indexd);
} else {
// Neither aa nor ad are equal to the current date being displayed
// So generate an empty record
$monthname = array('Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
$merged[$i] = array(
"downloads" => 0,
"dcountries" => 0,
"abstracts" => 0,
"acountries" => 0,
"month" => $monthname[$datei % 12],
// NJS 2006-06-14 BUG FIX: added () around the expression
// to ensure that the (int) is applied to the whole thing.
// We were getting fractional years in the output :(
"year" => (int) ( $datei / 12 )
);
}
// Progress: one more entry in $merged, and date earlier by one month
$i++;
$datei--;
}
return $merged;
}
/* ------------------------------------------------------------------------------
This function merges two country arrays, to produce a single consolidated array.
Note that either of the two arrays might be missing a country in the other.
(c) Copyright 2004 Arthur Sale, University of Tasmania
Precondition: both arrays are ordered in descending order of views.
Postcondition: result array contains records for every country in $aa and $ad,
and is ordered in descending order of download views.
------------------------------------------------------------------------------ */
function merge_countries($aa, &$ad)
// reference parameter $ad for efficiency, not changed,
// however the $aa value parameter is altered and is not prapogated back
{
$merged = array();
// Copy acrosss the download array, adding counts from the abstract array as needed.
for ($i=0; $i<count($ad); $i++) {
$merged[$i] = array(
"country_code" => $ad[$i]["country_code"],
"country_name" => $ad[$i]["country_name"],
"country_downloads" => $ad[$i]["count"],
"country_abstracts" => 0
);
$c_code = $merged[$i]["country_code"];
for ($j=0; $j<count($aa); $j++) {
if ($c_code == $aa[$j]["country_code"]) {
// matching country in abstracts
$merged[$i]["country_abstracts"] = $aa[$j]["count"];
// render this entry dead in future with reserved country code
$aa[$j]["country_code"] = '==';
// and get out of the loop
break;
}
} // for on $j
} // for on $i
// Copy what is left of the abstract array
$i = count($merged);
for ($j=0; $j<count($aa); $j++) {
if ($aa[$j]["country_code"] != '==') {
// country with only abstract views, so copy
$merged[$i] = array(
"country_code" => $aa[$j]["country_code"],
"country_name" => $aa[$j]["country_name"],
"country_downloads" => 0,
"country_abstracts" => $aa[$j]["count"]
);
// and increment $i
$i++;
}
} // for on $j
return $merged;
}
?>
