[42] | 1 | <?php |
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| 2 | /*======================================================================= |
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| 3 | // File: JPGRAPH_MESHINTERPOLATE.INC.PHP |
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| 4 | // Description: Utility class to do mesh linear interpolation of a matrix |
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| 5 | // Created: 2009-03-09 |
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| 6 | // Ver: $Id: jpgraph_meshinterpolate.inc.php 1709 2009-07-30 08:00:08Z ljp $ |
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| 7 | // |
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| 8 | // Copyright (c) Asial Corporation. All rights reserved. |
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| 9 | //======================================================================== |
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| 10 | */ |
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| 11 | |
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| 12 | /** |
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| 13 | * Utility function to do linear mesh interpolation |
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| 14 | * @param $aDat Matrix to interpolate |
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| 15 | * @param $aFactor Interpolation factor |
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| 16 | */ |
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| 17 | function doMeshInterpolate( &$aData, $aFactor ) { |
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| 18 | $m = new MeshInterpolate(); |
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| 19 | $aData = $m->Linear($aData,$aFactor); |
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| 20 | } |
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| 21 | |
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| 22 | /** |
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| 23 | * Utility class to interpolate a given data matrix |
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| 24 | * |
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| 25 | */ |
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| 26 | class MeshInterpolate { |
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| 27 | private $data = array(); |
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| 28 | |
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| 29 | /** |
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| 30 | * Calculate the mid points of the given rectangle which has its top left |
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| 31 | * corner at $row,$col. The $aFactordecides how many spliots should be done. |
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| 32 | * i.e. how many more divisions should be done recursively |
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| 33 | * |
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| 34 | * @param $row Top left corner of square to work with |
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| 35 | * @param $col Top left corner of square to work with |
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| 36 | * $param $aFactor In how many subsquare should we split this square. A value of 1 indicates that no action |
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| 37 | */ |
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| 38 | function IntSquare( $aRow, $aCol, $aFactor ) { |
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| 39 | if ( $aFactor <= 1 ) |
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| 40 | return; |
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| 41 | |
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| 42 | $step = pow( 2, $aFactor-1 ); |
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| 43 | |
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| 44 | $v0 = $this->data[$aRow][$aCol]; |
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| 45 | $v1 = $this->data[$aRow][$aCol + $step]; |
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| 46 | $v2 = $this->data[$aRow + $step][$aCol]; |
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| 47 | $v3 = $this->data[$aRow + $step][$aCol + $step]; |
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| 48 | |
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| 49 | $this->data[$aRow][$aCol + $step / 2] = ( $v0 + $v1 ) / 2; |
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| 50 | $this->data[$aRow + $step / 2][$aCol] = ( $v0 + $v2 ) / 2; |
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| 51 | $this->data[$aRow + $step][$aCol + $step / 2] = ( $v2 + $v3 ) / 2; |
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| 52 | $this->data[$aRow + $step / 2][$aCol + $step] = ( $v1 + $v3 ) / 2; |
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| 53 | $this->data[$aRow + $step / 2][$aCol + $step / 2] = ( $v0 + $v1 + $v2 + $v3 ) / 4; |
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| 54 | |
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| 55 | $this->IntSquare( $aRow, $aCol, $aFactor-1 ); |
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| 56 | $this->IntSquare( $aRow, $aCol + $step / 2, $aFactor-1 ); |
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| 57 | $this->IntSquare( $aRow + $step / 2, $aCol, $aFactor-1 ); |
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| 58 | $this->IntSquare( $aRow + $step / 2, $aCol + $step / 2, $aFactor-1 ); |
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| 59 | } |
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| 60 | |
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| 61 | /** |
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| 62 | * Interpolate values in a matrice so that the total number of data points |
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| 63 | * in vert and horizontal axis are $aIntNbr more. For example $aIntNbr=2 will |
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| 64 | * make the data matrice have tiwce as many vertical and horizontal dta points. |
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| 65 | * |
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| 66 | * Note: This will blow up the matrcide in memory size in the order of $aInNbr^2 |
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| 67 | * |
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| 68 | * @param $ &$aData The original data matricde |
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| 69 | * @param $aInNbr Interpolation factor |
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| 70 | * @return the interpolated matrice |
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| 71 | */ |
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| 72 | function Linear( &$aData, $aIntFactor ) { |
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| 73 | $step = pow( 2, $aIntFactor-1 ); |
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| 74 | |
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| 75 | $orig_cols = count( $aData[0] ); |
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| 76 | $orig_rows = count( $aData ); |
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| 77 | // Number of new columns/rows |
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| 78 | // N = (a-1) * 2^(f-1) + 1 |
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| 79 | $p = pow( 2, $aIntFactor-1 ); |
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| 80 | $new_cols = $p * ( $orig_cols - 1 ) + 1; |
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| 81 | $new_rows = $p * ( $orig_rows - 1 ) + 1; |
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| 82 | |
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| 83 | $this->data = array_fill( 0, $new_rows, array_fill( 0, $new_cols, 0 ) ); |
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| 84 | // Initialize the new matrix with the values that we know |
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| 85 | for ( $i = 0; $i < $new_rows; $i++ ) { |
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| 86 | for ( $j = 0; $j < $new_cols; $j++ ) { |
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| 87 | $v = 0 ; |
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| 88 | if ( ( $i % $step == 0 ) && ( $j % $step == 0 ) ) { |
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| 89 | $v = $aData[$i / $step][$j / $step]; |
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| 90 | } |
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| 91 | $this->data[$i][$j] = $v; |
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| 92 | } |
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| 93 | } |
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| 94 | |
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| 95 | for ( $i = 0; $i < $new_rows-1; $i += $step ) { |
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| 96 | for ( $j = 0; $j < $new_cols-1; $j += $step ) { |
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| 97 | $this->IntSquare( $i, $j, $aIntFactor ); |
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| 98 | } |
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| 99 | } |
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| 100 | |
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| 101 | return $this->data; |
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| 102 | } |
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| 103 | } |
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| 104 | |
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| 105 | ?> |
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