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Log.htm

Log.htm 1.6 KB
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  1. <html>
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  2. <head>
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  3. <title>Blitz3D Docs</title>
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  4. <link rel=stylesheet href=../css/commands.css type=text/css>
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  5. </head>
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  6. <body>
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  7. <h1>Log# ( x# )</h1>
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  8. <h1>Parameters</h1>
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  9. <table>
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  10. <tr>
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  11. <td>
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  12. x = any positive number.
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  13. </td>
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  14. </tr>
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  15. </table>
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  16. <h1>Description</h1>
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  17. <table>
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  18. <tr>
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  19. <td>
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  20. Natural logarithm of x. This is the inverse of Exp( ).

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  21. 
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  22. y = Log( x ) means y satifies x = Exp( y ).

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  23. 
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  24. The base of the natural logarithm is e = Exp(1) = 2.71828...

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  25. 
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  26. See also Exp()
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  27. </td>
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  28. </tr>
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  29. </table>
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  30. <h1><a href=../2d_examples/Log.bb>Example</a></h1>
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  31. <table>
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  32. <tr>
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  33. <td>
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  34. ; Log example
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  35. 
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  36. ; NaN means "Not a Number", the numerical result is invalid.
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  37. 
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  38. ; NOTE: All logarithm functions are related. For example, there is no
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  39. ;       Log8 function in Blitz, but we can easily make one.
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  40. 
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  41. HidePointer
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  42. 
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  43. Print "Log8( -1 ) = " + Log8( -1 )
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  44. Print "Log8( 0  ) = " + Log8( 0 )
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  45. Print
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  46. 
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  47. ; ... and now some well behaved numbers...
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  48. 
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  49. x# = 1.0 / 4096.0   ; small positive number
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  50. 
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  51. For n = 1 To 15
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  52. 
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  53. Print "Log8( " + LSet( x, 13 ) + " ) = " + Log8( x )
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  54. x = 8 * x
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  55. 
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  56. Next
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  57. 
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  58. WaitKey()  :  End
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  59. 
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  60. 
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  61. Function Log8# ( x# )
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  62. 
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  63. Return Log( x ) / Log( 8 )
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  64. 
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  65. End Function
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  66. </td>
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  67. </tr>
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  68. </table>
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  69. <br>
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  70. <a target=_top href=../index.htm>Index</a><br>
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  71. <br>
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  72. Click <a href=http://www.blitzbasic.co.nz/b3ddocs/command.php?name=Log&ref=comments target=_blank>here</a> to view the latest version of this page online</body>
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  73. </html>
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