PHPOffice /
PhpSpreadsheet
| @@ 1014-1046 (lines=33) @@ | ||
| 1011 | * |
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| 1012 | * @return float |
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| 1013 | */ |
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| 1014 | public static function BESSELK($x, $ord) |
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| 1015 | { |
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| 1016 | $x = (is_null($x)) ? 0.0 : Functions::flattenSingleValue($x); |
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| 1017 | $ord = (is_null($ord)) ? 0.0 : Functions::flattenSingleValue($ord); |
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| 1018 | ||
| 1019 | if ((is_numeric($x)) && (is_numeric($ord))) { |
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| 1020 | if (($ord < 0) || ($x == 0.0)) { |
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| 1021 | return Functions::NAN(); |
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| 1022 | } |
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| 1023 | ||
| 1024 | switch (floor($ord)) { |
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| 1025 | case 0: |
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| 1026 | $fBk = self::besselK0($x); |
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| 1027 | break; |
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| 1028 | case 1: |
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| 1029 | $fBk = self::besselK1($x); |
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| 1030 | break; |
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| 1031 | default: |
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| 1032 | $fTox = 2 / $x; |
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| 1033 | $fBkm = self::besselK0($x); |
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| 1034 | $fBk = self::besselK1($x); |
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| 1035 | for ($n = 1; $n < $ord; ++$n) { |
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| 1036 | $fBkp = $fBkm + $n * $fTox * $fBk; |
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| 1037 | $fBkm = $fBk; |
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| 1038 | $fBk = $fBkp; |
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| 1039 | } |
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| 1040 | } |
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| 1041 | ||
| 1042 | return (is_nan($fBk)) ? Functions::NAN() : $fBk; |
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| 1043 | } |
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| 1044 | ||
| 1045 | return Functions::VALUE(); |
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| 1046 | } |
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| 1047 | ||
| 1048 | private static function besselY0($fNum) |
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| 1049 | { |
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| @@ 1101-1133 (lines=33) @@ | ||
| 1098 | * |
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| 1099 | * @return float |
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| 1100 | */ |
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| 1101 | public static function BESSELY($x, $ord) |
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| 1102 | { |
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| 1103 | $x = (is_null($x)) ? 0.0 : Functions::flattenSingleValue($x); |
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| 1104 | $ord = (is_null($ord)) ? 0.0 : Functions::flattenSingleValue($ord); |
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| 1105 | ||
| 1106 | if ((is_numeric($x)) && (is_numeric($ord))) { |
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| 1107 | if (($ord < 0) || ($x == 0.0)) { |
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| 1108 | return Functions::NAN(); |
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| 1109 | } |
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| 1110 | ||
| 1111 | switch (floor($ord)) { |
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| 1112 | case 0: |
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| 1113 | $fBy = self::besselY0($x); |
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| 1114 | break; |
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| 1115 | case 1: |
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| 1116 | $fBy = self::besselY1($x); |
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| 1117 | break; |
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| 1118 | default: |
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| 1119 | $fTox = 2 / $x; |
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| 1120 | $fBym = self::besselY0($x); |
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| 1121 | $fBy = self::besselY1($x); |
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| 1122 | for ($n = 1; $n < $ord; ++$n) { |
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| 1123 | $fByp = $n * $fTox * $fBy - $fBym; |
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| 1124 | $fBym = $fBy; |
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| 1125 | $fBy = $fByp; |
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| 1126 | } |
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| 1127 | } |
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| 1128 | ||
| 1129 | return (is_nan($fBy)) ? Functions::NAN() : $fBy; |
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| 1130 | } |
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| 1131 | ||
| 1132 | return Functions::VALUE(); |
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| 1133 | } |
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| 1134 | ||
| 1135 | /** |
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| 1136 | * BINTODEC. |
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