php根据词频生成tag云

给定一段文本，此代码分析文本的词频分布，生成tag云

1. /**
2. * Tag cloud demo based on word frequency
3. * @author: unknown
4. * @since: 2007-02-27
5. */
7. // Store frequency of words in an array
8. $freqData = array();
10. // Random words
11. $lorem = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
12. Phasellus vestibulum ullamcorper tortor. Aenean quis lacus quis neque
13. adipiscing ultricies. Pellentesque tincidunt ligula vitae nibh ornare
14. pharetra. Proin dignissim tortor. Donec et ipsum nec tellus gravida
15. tempor. Aliquam ullamcorper purus vel felis. Praesent faucibus.
16. Curabitur porta. Nulla in lorem quis mi lacinia fringilla. Integer
17. adipiscing mi quis felis. Pellentesque habitant morbi tristique senectus
18. et netus et malesuada fames ac turpis egestas. Quisque sagittis ante in
19. arcu. Sed libero enim, venenatis sit amet, vestibulum at, porttitor id,
20. neque. Vestibulum ornare semper erat. Sed tincidunt nibh et massa. Cras
21. sed diam. Quisque blandit enim.
24. Sed nonummy. Aenean mollis turpis quis enim. Nam massa nulla, varius
25. molestie, aliquet et, feugiat eget, nisi. Sed mollis, leo ut pretium
26. placerat, nibh turpis egestas ipsum, sed aliquam neque enim in risus.
27. Nullam nisl. Sed tincidunt leo quis tellus. Mauris non lorem. Aenean
28. tristique justo at arcu. Fusce et lorem. Nam sodales. Mauris condimentum
29. diam. Nam commodo. Cum sociis natoque penatibus et magnis dis parturient
30. montes, nascetur ridiculus mus. Cras ac risus. Proin et dolor laoreet mi
31. gravida sodales. Duis bibendum, ipsum posuere egestas posuere, dui lacus
32. feugiat turpis, id tincidunt urna est sit amet est. Cras eu sem.
33. ";
35. // Get individual words and build a frequency table
36. foreach( str_word_count( $lorem, 1 ) as $word )
37. {
38. // For each word found in the frequency table, increment its value by one
39. array_key_exists( $word, $freqData ) ? $freqData[ $word ]++ : $freqData[ $word ] = 0;
40. }
42. // ==============================================================
43. // = Function to actually generate the cloud from provided data =
44. // ==============================================================
45. function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 )
46. {
47. $minimumCount = min( array_values( $data ) );
48. $maximumCount = max( array_values( $data ) );
49. $spread = $maximumCount - $minimumCount;
50. $cloudHTML = '';
51. $cloudTags = array();
53. $spread == 0 && $spread = 1;
55. foreach( $data as $tag => $count )
56. {
57. $size = $minFontSize + ( $count - $minimumCount )
58. * ( $maxFontSize - $minFontSize ) / $spread;
59. $cloudTags[] = ' . '" class="tag_cloud" href="http://www.google.com/search?q=' . $tag
60. . '" title="\'' . $tag . '\' returned a count of ' . $count . '">'
61. . htmlspecialchars( stripslashes( $tag ) ) . '';
62. }
64. return join( "\n", $cloudTags ) . "\n";
65. }
66. ?>
67. "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

76. Sample Tag Cloud