<br /> /** rotate a string, use for simple encoding */<br /> function rotateString($pInput,$pRotateNum=0) {<br /> $vOutput = ”;<br /> $vStr = ‘abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890|’;<br /> $vLen = strlen($vStr);<br /> for ($i=0;$i<strlen($pInput);$i++) {<br /> $vIndex = strpos($vStr,$pInput{$i});<br /> if ($vIndex===FALSE) { // non-encode chars, leave these alone<br /> $vOutput .= $pInput{$i};<br /> } else {<br /> $vIndex = $vIndex+$pRotateNum;<br /> $vIndex = $vIndex>0?$vIndex%$vLen:($vLen+$vIndex)%$vLen;<br /> $vOutput .= $vStr{$vIndex};<br /> } // fi<br /> } // rof<br /> //var_dump($vOutput);<br /> return $vOutput;<br /> }<br />

Usage

$a = rotateString($b,19); // encode
$b = rotateString($a,-19); // decode

This PHP 5 class forecasts future values from past data. It takes into account the growth trend, seasonality and irregularity (noise) in input data. This class uses an external class: linear regression analysis

<br /> <?php<br /> /** A time-series forcasting, given a series of data (w/ seasonal data), predict future data<br /> * Src: http://home.ubalt.edu/ntsbarsh/stat-data/Forecast.htm & BUS264 (Oliver Yu's coursenote)<br /> * @author Son Nguyen<br /> * @since 10/1/2008<br /> * @package Framework<br /> * @subpackage Math<br /> */<br /> class CMathForecasting {<br /> private $mPastDatas; // array of data (eg: x1,x2,x3,x4...)<br /> private $mNumSeasons; // the number of seasons to consider (eg: 4 quarters/year, 7 days/week, 24 hours/day)<br /> /** constructor */<br /> function __construct($pPastDatas,$pNumSeasons) {<br /> $this->mPastDatas = $pPastDatas;<br /> $this->mNumSeasons = $pNumSeasons;<br /> }</p> <p> /** compute the n-season moving average */<br /> function computeSMA() {<br /> $vSMA = array();<br /> for ($i=0;$i<count($this->mPastDatas);$i++) {<br /> if ($i+$this->mNumSeasons-1>=count($this->mPastDatas)) { // out of bound, done<br /> break;<br /> } // fi</p> <p> $vSum = 0;<br /> for ($j=0;$j<$this->mNumSeasons;$j++) {<br /> $vSum += $this->mPastDatas[$i+$j];<br /> } // rof<br /> $vSMA[] = $vSum/$this->mNumSeasons;<br /> } // rof<br /> return $vSMA;<br /> }</p> <p> /** compute centered moving average from the n-season moving average */<br /> function computeCMA($pSMA) {<br /> $vCMA = array();<br /> for ($i=0;$i<count($pSMA);$i++) {<br /> if ($i+1>=count($pSMA)) { // out of bound, done<br /> break;<br /> } // fi<br /> $vCMA[] = ($pSMA[$i]+$pSMA[$i+1])/2;<br /> } // rof<br /> return $vCMA;<br /> }</p> <p> /** season irregularity */<br /> function computeNoises($pCMA) {<br /> $vNoises = array();<br /> for ($i=0;$i<count($pCMA);$i++) {<br /> $vStarting = floor($this->mNumSeasons/2);<br /> $vNoises[] = $this->mPastDatas[$i+$vStarting]/$pCMA[$i];<br /> } // rof<br /> return $vNoises;<br /> }</p> <p> /** comment */<br /> function computeSeasonIndices($pNoises) {<br /> $vIndices = array();<br /> for ($i=0;$i<$this->mNumSeasons;$i++) {<br /> $vSum = array();<br /> for ($j=$i;$j<count($pNoises);$j+=$this->mNumSeasons) {<br /> $vSum[] = $pNoises[$j];<br /> } // rof<br /> $vStarting = (floor($this->mNumSeasons/2)+$i)%$this->mNumSeasons;<br /> $vIndices[$vStarting] = array_sum($vSum)/count($vSum);<br /> } // rof</p> <p> ksort($vIndices);</p> <p> // also adjust these season indices<br /> $vSum = array_sum($vIndices);<br /> for ($i=0;$i<count($vIndices);$i++) {<br /> $vIndices[$i] = $vIndices[$i]*$this->mNumSeasons/$vSum;<br /> } // rof<br /> return $vIndices;<br /> }</p> <p> /** comment */<br /> function computeDeSeasonalized($pSeasonIndex) {<br /> $vDatas = array();</p> <p> for ($i=0;$i<count($this->mPastDatas);$i++) {<br /> $vDatas[] = $this->mPastDatas[$i]/$pSeasonIndex[$i%$this->mNumSeasons];<br /> } // rof<br /> return $vDatas;<br /> }</p> <p> /** how many future periods to predict */<br /> function predict($pNumFuturePeriods) {<br /> $vSMA = $this->computeSMA();<br /> if ($this->mNumSeasons%2==0) { // even<br /> $vCMA = $this->computeCMA($vSMA);<br /> } else { // odd, nSMA=CMA<br /> $vCMA = $vSMA;<br /> } // fi</p> <p> $vNoises = $this->computeNoises($vCMA);<br /> $vIndices = $this->computeSeasonIndices($vNoises);</p> <p> $vDeSeasonalized = $this->computeDeSeasonalized($vIndices);</p> <p> // perform regression to get the trend line<br /> $vRegression = new CRegressionLinear($vDeSeasonalized);<br /> list($vXVar,$vIntercept) = $vRegression->calculate();</p> <p> $vForecast = array();<br /> for ($i=0;$i<$pNumFuturePeriods;$i++) {<br /> $vForecast[] = $vIntercept + $vXVar*(count($this->mPastDatas)+$i);<br /> } // rof</p> <p> // have to re-seasonalized these values<br /> for ($i=0;$i<count($vForecast);$i++) {<br /> $vForecast[$i] = $vForecast[$i]*$vIndices[(count($this->mPastDatas)+$i)%$this->mNumSeasons];<br /> } // rof</p> <p> return $vForecast;</p> <p> }<br /> }<br /> ?><br />

Sample Usage

<br /> <?php<br /> include('math.reg.linear.class.php');<br /> include('math.forecasting.class.php');</p> <p>// Example #1: daily sales number for the past 30 days<br /> $vSales = array(<br /> 637381,700986,641305,660285,604474,565316,598734,688690,723406,697358,<br /> 669910,605636,526655,555165,625800,579405,588317,634433,628443,570597,<br /> 662584,763516,742150,703209,669883,586504,489240,648875,692212,586509<br /> );</p> <p>$vForecast = new CMathForecasting($vSales,7); // sales pattern is weekly<br /> $vResult = $vForecast->predict(7); // predict the next 7 days<br /> var_dump($vResult);</p> <p>// Example #2: quarterly demand number (x1000 units)<br /> $vSales = array(<br /> 3,9,6,2,<br /> 4,11,8,3,<br /> 5,15,11,3<br /> );</p> <p>$vForecast = new CMathForecasting($vSales,4); // sales pattern is quarterly<br /> $vResult = $vForecast->predict(4); // predict the next 4 quarters<br /> var_dump($vResult);<br /> ?><br />

With JSONP, you can avoid the “Access is Denied” problem when loading a remote AJAX request. jQuery 1.2.x now supports JSONP, you can use that or this simple code snippet. In this example, let’s assume you’re on a page with a remote javascript loaded, now you only want this remote script to reload, not the whole page.

<br /> function reloadJS() {<br /> var url = ‘http://example.com/getJSON.php?id=1234′;<br /> var js = document.createElement(“script”);<br /> js.setAttribute(“src”,url+”&CacheBuster=”+Math.random());<br /> js.setAttribute(“type”,”text/javascript”);<br /> document.body.appendChild(js);<br /> }</p> <p>function ajaxJSONCallback(data) {<br /> document.getElementById(“SomeDivID”).innerHTML = data.SomeData;<br /> }</p> <p>window.setInterval(“reloadJS()”,10000);</p> <p>

And the result of getJSON.php:
<br /> ajaxJSONCallback({“SomeData”:” <p>Test Output</p> <p>“});<br />

Given a content string, this class uses Yahoo Term Extraction API to generate a list of keywords/phrases that you can use for things like META tags or other SEO objectives.

<br /> <?php<br /> /**<br /> * @author Son Nguyen<br /> * @since 2/13/2006<br /> * @package Framework<br /> * @subpackage WebServices<br /> */<br /> class CYahooTermExtraction extends CYahooAPI {<br /> private $mContext; // string, get main keywords from this text<br /> /** constructor */<br /> function __construct($pContext) {<br /> $this->mServiceURL = ‘http://api.search.yahoo.com/ContentAnalysisService/V1/termExtraction’;<br /> $this->mContext = $pContext;<br /> }</p> <p> /** get the tags/keywords through Yahoo API */<br /> function fetchTags() {<br /> $vReq = new CHTTPRequest($this->mServiceURL);<br /> $vReq->addQueryString(‘appid’,$this->mAppID);<br /> $vReq->addQueryString(‘context’,$this->mContext);<br /> list($vHeader,$vBody) = $vReq->sendPOST();<br /> //var_dump($vHeader,$vBody);die;<br /> $vXML = simplexml_load_string($vBody);<br /> $vTmp = array();<br /> foreach ($vXML->Result AS $vOne) {<br /> $vTmp[] = (string)$vOne;<br /> } // rof<br /> return $vTmp; // an array of tags<br /> }</p> <p> /** comment */<br /> function display() {<br /> $vTags = $this->fetchTags();<br /> return implode(‘, ‘,$vTags);<br /> }<br /> }<br /> ?></p> <p><?php<br /> /**<br /> * @author Son Nguyen<br /> * @since 3/21/2006<br /> * @package Framework<br /> * @subpackage WebServices<br /> */<br /> class CYahooAPI {<br /> protected $mAppID = 'YourYahooApplicationID';<br /> protected $mServiceURL;</p> <p> /** constructor */<br /> function __construct() {</p> <p> }<br /> }<br /> ?></p> <p>

This class parses, fixes and prepares php_browscap.ini into browscap.ini for PHP. It also detects if the latest version needed to download.

<br /> <?php<br /> /** from localhost to fetch and prepare the browscap.ini file<br /> * @author Son Nguyen<br /> * @since 8/25/2006<br /> * @package Framework<br /> * @subpackage Lookup<br /> */<br /> class CBrowsCap {<br /> private $mTmpFileName = 'php_browscap.ini'; // tmp file before fixing<br /> private $mDownloadURL = 'http://browsers.garykeith.com/stream.asp?PHP_BrowsCapINI';<br /> /** constructor */<br /> function __construct() {}</p> <p> /** get the version string from the file */<br /> function getVersion($pFile,$pCheckExisted) {<br /> $vVersion = NULL;<br /> if ($pCheckExisted && !file_exists($pFile)) {<br /> return NULL;<br /> } // fi</p> <p> $vContent = file_get_contents($pFile,FALSE,NULL,0,500);<br /> if (preg_match('/version=(.*)/i',$vContent,$vMatches)) {<br /> $vVersion = trim($vMatches[1]);<br /> } // fi<br /> return $vVersion;<br /> }</p> <p> /** comment */<br /> function getLatestVersion() {<br /> return $this->getVersion($this->mDownloadURL,FALSE);<br /> }</p> <p> /** get the current I’m currently use */<br /> function getMyVersion() {<br /> return $this->getVersion($this->mTmpFileName,TRUE);<br /> }</p> <p> /** if need to update */<br /> function checkUpdate() {<br /> $vMy = $this->getMyVersion();<br /> $vLatest = $this->getLatestVersion();<br /> if (!file_exists($this->mTmpFileName) || $vMy<$vLatest) { // should update<br /> $vContent = file_get_contents($this->mDownloadURL);<br /> file_put_contents($this->mTmpFileName,$vContent);<br /> return ‘Updated to version #’.$vLatest.’ from #’.$vMy; // yes, do update<br /> } // fi</p> <p> return ‘Already at the latest version #’.$vLatest; // latest, don’t update<br /> }</p> <p> /** fix the browsecap.ini for php */<br /> function fix() {<br /> $vOutput = $this->checkUpdate();</p> <p> $vContent = file_get_contents($this->mTmpFileName);<br /> $vContent = preg_replace(“/\r/”,”",$vContent);<br /> $vContent = preg_replace(‘/=”(.*)”/i’,'=\\1′,$vContent);<br /> $vContent = preg_replace(“/platform=(.*)/i”,”platform=\”\\1\”",$vContent);<br /> $vContent = preg_replace(“/parent=(.*)/i”,”parent=\”\\1\”",$vContent);<br /> $vContent = preg_replace(“/minorver=(.*)/i”,”minorver=\”\\1\”",$vContent);<br /> $vContent = preg_replace(“/majorver=(.*)/i”,”majorver=\”\\1\”",$vContent);<br /> $vContent = preg_replace(“/version=(.*)/i”,”version=\”\\1\”",$vContent);<br /> $vContent = preg_replace(“/browser=(.*)/i”,”browser=\”\\1\”",$vContent);<br /> $vContent = str_replace(“[*]“,”*”,$vContent);<br /> file_put_contents(‘browscap.ini’,$vContent);</p> <p> return $vOutput;<br /> }<br /> }<br /> ?><br />

Developers can use the browscap.ini to detect if the User-Agent is a search engine or data collection spider or not. However, that file is rather large and will be expensive on resources. If you need a faster, simpler (albeit less accurate) method, this class can be useful.

<br /> <?php<br /> /** a quick/less resource intensive browser detection<br /> * @author Son Nguyen<br /> * @since 1/29/2007<br /> * @package Framework<br /> * @subpackage Misc<br /> */<br /> class CBrowserDetect {<br /> private $mUA;<br /> /** constructor */<br /> function __construct($pUA=NULL) {<br /> $this->setUA($pUA);<br /> }</p> <p> /** comment */<br /> function setUA($pUA=NULL) {<br /> if (is_null($pUA) && isset($_SERVER['HTTP_USER_AGENT'])) {<br /> $this->mUA = $_SERVER['HTTP_USER_AGENT'];<br /> } else {<br /> $this->mUA = $pUA;<br /> } // fi<br /> }</p> <p> /** if this is a spider/crawler */<br /> function isSpider($pUA=NULL) {<br /> $this->setUA($pUA);<br /> $vBots = array(<br /> ‘AdsBot-Google’,<br /> ‘alexa’,<br /> ‘appie’,<br /> ‘Ask Jeeves’,<br /> ‘Baiduspider’,<br /> ‘crawler’,<br /> ‘FAST’,<br /> ‘Firefly’,<br /> ‘froogle’,<br /> ‘girafabot’,<br /> ‘Googlebot’,<br /> ‘ia_archiver’,<br /> ‘InfoSeek’,<br /> ‘inktomi’,<br /> ‘Java/’,<br /> ‘looksmart’,<br /> ‘msnbot’,<br /> ‘NationalDirectory’,<br /> ‘rabaz’,<br /> ‘Scooter’,<br /> ‘Slurp’,<br /> ‘Spade’,<br /> ‘TECNOSEEK’,<br /> ‘Teoma’,<br /> ‘URL_Spider_SQL’,<br /> ‘WebBug’,<br /> ‘WebCapture’,<br /> ‘WebFindBot’,<br /> ‘Wget/’,<br /> ‘ZyBorg’,<br /> ‘libwww-perl/’,<br /> ‘httpunit/’,<br /> ‘WebZIP/’,<br /> );<br /> foreach ($vBots AS $vPat) {<br /> if (stripos($this->mUA,$vPat)!==FALSE) {<br /> return TRUE;<br /> } // fi<br /> } // rof<br /> return FALSE;<br /> }<br /> }<br /> ?><br />