What is the best way to create a tag cloud from an array using h1-h6 to determine the size?

Question

I have the following arrays:

$artist = array("the roots", "michael jackson", "billy idol", "more", "and more", "and_YET_MORE"); $count = array(5, 3, 9, 1, 1, 3); 

I want to create a tag cloud in which there will be artists with a large number in $count , enclosed in h6 tags, and h1 tags with the smallest attachment.

Answer 1

You will also want to add a logarithmic function to it. (taken from tagadelic, my Drupal module for creating tag clouds is http://drupal.org/project/tagadelic ):

 db_query('SELECT COUNT(*) AS count, id, name FROM ... ORDER BY count DESC'); $steps = 6; $tags = array(); $min = 1e9; $max = -1e9; while ($tag = db_fetch_object($result)) { $tag->number_of_posts = $tag->count; #sets the amount of items a certain tag has attached to it $tag->count = log($tag->count); $min = min($min, $tag->count); $max = max($max, $tag->count); $tags[$tag->tid] = $tag; } // Note: we need to ensure the range is slightly too large to make sure even // the largest element is rounded down. $range = max(.01, $max - $min) * 1.0001; foreach ($tags as $key => $value) { $tags[$key]->weight = 1 + floor($steps * ($value->count - $min) / $range); } 

Then in your view or template:

 foreach ($tags as $tag) { $output .= "<h$tag->weight>$tag->name</h$tag->weight>" } 

Answer 2

Over my head ...

 $artist = array("the roots","michael jackson","billy idol","more","and more","and_YET_MORE"); $count = array(5,3,9,1,1,3); $highest = max($count); for (int $x = 0; x < count($artist); $x++) { $normalized = $count[$x] / $highest; $heading = ceil($normalized * 6); // 6 heading types echo "<h".$heading.">".$artist[$x]."</h".$heading.">"; } 

Answer 3

This may be a small academic and non-standard topic, but hX tags hX probably not the best choice for a tag cloud for reasons of document structure and all that.

Maybe span or ol with the appropriate class attributes (plus some CSS)?

Answer 4

For some time they used this fragment, credit - prism-perfect.net. Doesn't use H tags, though

 <div id="tags"> <div class="title">Popular Searches</div> <?php // Snippet taken from [prism-perfect.net] include "/path/to/public_html/search/settings/database.php"; include "/path/to/public_html/search/settings/conf.php"; $query = "SELECT query AS tag, COUNT(*) AS quantity FROM sphider_query_log WHERE results > 0 GROUP BY query ORDER BY query ASC LIMIT 10"; $result = mysql_query($query) or die(mysql_error()); while ($row = mysql_fetch_array($result)) { $tags[$row['tag']] = $row['quantity']; } // change these font sizes if you will $max_size = 30; // max font size in % $min_size = 11; // min font size in % // get the largest and smallest array values $max_qty = max(array_values($tags)); $min_qty = min(array_values($tags)); // find the range of values $spread = $max_qty - $min_qty; if (0 == $spread) { // we don't want to divide by zero $spread = 1; } // determine the font-size increment // this is the increase per tag quantity (times used) $step = ($max_size - $min_size)/($spread); // loop through our tag array foreach ($tags as $key => $value) { // calculate CSS font-size // find the $value in excess of $min_qty // multiply by the font-size increment ($size) // and add the $min_size set above $size = $min_size + (($value - $min_qty) * $step); // uncomment if you want sizes in whole %: // $size = ceil($size); // you'll need to put the link destination in place of the /search/search.php... // (assuming your tag links to some sort of details page) echo '<a href="/search/search.php?query='.$key.'&search=1" style="font-size: '.$size.'px"'; // perhaps adjust this title attribute for the things that are tagged echo ' title="'.$value.' things tagged with '.$key.'"'; echo '>'.$key.'</a> '; // notice the space at the end of the link } ?> </div> 

Answer 5

@Ryan

This is correct, but actually makes the tags with the smallest number larger. This code has been tested:

 $artist = array("the roots","michael jackson","billy idol","more","and more","and_YET_MORE"); $count = array(5,3,9,1,1,3); $highest = max($count); for ($x = 0; $x < count($artist); $x++) { $normalized = ($highest - $count[$x]+1) / $highest; $heading = ceil($normalized * 6); // 6 heading types echo "<h$heading>{$artist[$x]}</h$heading>"; } 

Answer 6

This method is intended for SQL/PostgreSQL fanatics. It does all the work in the database and prints the text using the "slugified" link. It uses Doctrine ORM only for sql call, I do not use objects. Suppose we have 10 sizes:

 public function getAllForTagCloud($fontSizes = 10) { $sql = sprintf("SELECT count(tag) as tagcount,tag,slug, floor((count(*) * %d )/(select max(t) from (select count(tag) as t from magazine_tag group by tag) t)::numeric(6,2)) as ranking from magazine_tag mt group by tag,slug", $fontSizes); $q = Doctrine_Manager::getInstance()->getCurrentConnection(); return $q->execute($sql); } 

then you print them with some CSS class, from .tagranking10 (best) to .tagranking1 (worst):

 <?php foreach ($allTags as $tag): ?> <span class="<?php echo 'tagrank'.$tag['ranking'] ?>"> <?php echo sprintf('<a rel="tag" href="/search/by/tag/%s">%s</a>', $tag['slug'], $tag['tag'] ); ?> </span> <?php endforeach; ?> 

and this is CSS :

 /* put your size of choice */ .tagrank1{font-size: 0.3em;} .tagrank2{font-size: 0.4em;} .tagrank3{font-size: 0.5em;} /* go on till tagrank10 */ 

This method displays all tags. If you have a lot of them, you probably do not want the tag cloud to become a tag. In this case, you must add the HAVING TO to your SQL query:

 -- minimum tag count is 8 -- HAVING count(tag) > 7 

What all

Answer 7

As an assistant in Rails:

 def tag_cloud (strings, counts) max = counts.max strings.map { |a| "<span style='font-size:#{((counts[strings.index(a)] * 4.0)/max).ceil}em'>#{a}</span> " } end 

Call this from a view:

 <%= tag_cloud($artists, $counts) %> 

This prints out the <span style='font-size:_em'> in the array, which will be converted to a string in the view, in order to do this:

 <span style='font-size:3em'>the roots</span> <span style='font-size:2em'>michael jackson</span> <span style='font-size:4em'>billy idol</span> <span style='font-size:1em'>more</span> <span style='font-size:1em'>and more</span> <span style='font-size:2em'>and_YET_MORE</span> 

It is better to have a class attribute and refer to classes in the stylesheet, as mentioned by Brendan. Much better than using h1-h6 semantically and there is less style baggage with <span> .

Answer 8

I know his very old post. posting my opinion as this may help someone in the future.

Here is the cloud tag that I used on my website http://www.vbausefulcodes.in/

 <?php $input= array("vba","macros","excel","outlook","powerpoint","access","database","interview questions","sendkeys","word","excel projects","visual basic projects","excel vba","macro","excel visual basic","tutorial","programming","learn macros","vba examples"); $rand_tags = array_rand($input, 5); for ($x = 0; $x <= 4; $x++) { $size = rand ( 1 , 4 ); echo "<font size='$size'>" . $input[$rand_tags[$x]] . " " . "</font>"; } echo "<br>"; $rand_tags = array_rand($input, 7); for ($x = 0; $x <= 6; $x++) { $size = rand ( 1 , 4 ); echo "<font size='$size'>" . $input[$rand_tags[$x]] . " " . "</font>"; } echo "<br>"; $rand_tags = array_rand($input, 5); for ($x = 0; $x <= 4; $x++) { $size = rand ( 1 , 4 ); echo "<font size='$size'>" . $input[$rand_tags[$x]] . " " . "</font>"; } ?>