PHPOffice /
PhpSpreadsheet
| @@ 994-1028 (lines=35) @@ | ||
| 991 | * |
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| 992 | * @return float |
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| 993 | */ |
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| 994 | public static function BESSELK($x, $ord) |
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| 995 | { |
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| 996 | $x = ($x === null) ? 0.0 : Functions::flattenSingleValue($x); |
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| 997 | $ord = ($ord === null) ? 0.0 : Functions::flattenSingleValue($ord); |
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| 998 | ||
| 999 | if ((is_numeric($x)) && (is_numeric($ord))) { |
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| 1000 | if (($ord < 0) || ($x == 0.0)) { |
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| 1001 | return Functions::NAN(); |
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| 1002 | } |
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| 1003 | ||
| 1004 | switch (floor($ord)) { |
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| 1005 | case 0: |
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| 1006 | $fBk = self::besselK0($x); |
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| 1007 | ||
| 1008 | break; |
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| 1009 | case 1: |
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| 1010 | $fBk = self::besselK1($x); |
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| 1011 | ||
| 1012 | break; |
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| 1013 | default: |
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| 1014 | $fTox = 2 / $x; |
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| 1015 | $fBkm = self::besselK0($x); |
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| 1016 | $fBk = self::besselK1($x); |
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| 1017 | for ($n = 1; $n < $ord; ++$n) { |
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| 1018 | $fBkp = $fBkm + $n * $fTox * $fBk; |
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| 1019 | $fBkm = $fBk; |
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| 1020 | $fBk = $fBkp; |
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| 1021 | } |
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| 1022 | } |
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| 1023 | ||
| 1024 | return (is_nan($fBk)) ? Functions::NAN() : $fBk; |
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| 1025 | } |
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| 1026 | ||
| 1027 | return Functions::VALUE(); |
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| 1028 | } |
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| 1029 | ||
| 1030 | private static function besselY0($fNum) |
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| 1031 | { |
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| @@ 1083-1117 (lines=35) @@ | ||
| 1080 | * |
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| 1081 | * @return float |
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| 1082 | */ |
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| 1083 | public static function BESSELY($x, $ord) |
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| 1084 | { |
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| 1085 | $x = ($x === null) ? 0.0 : Functions::flattenSingleValue($x); |
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| 1086 | $ord = ($ord === null) ? 0.0 : Functions::flattenSingleValue($ord); |
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| 1087 | ||
| 1088 | if ((is_numeric($x)) && (is_numeric($ord))) { |
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| 1089 | if (($ord < 0) || ($x == 0.0)) { |
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| 1090 | return Functions::NAN(); |
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| 1091 | } |
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| 1092 | ||
| 1093 | switch (floor($ord)) { |
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| 1094 | case 0: |
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| 1095 | $fBy = self::besselY0($x); |
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| 1096 | ||
| 1097 | break; |
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| 1098 | case 1: |
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| 1099 | $fBy = self::besselY1($x); |
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| 1100 | ||
| 1101 | break; |
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| 1102 | default: |
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| 1103 | $fTox = 2 / $x; |
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| 1104 | $fBym = self::besselY0($x); |
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| 1105 | $fBy = self::besselY1($x); |
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| 1106 | for ($n = 1; $n < $ord; ++$n) { |
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| 1107 | $fByp = $n * $fTox * $fBy - $fBym; |
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| 1108 | $fBym = $fBy; |
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| 1109 | $fBy = $fByp; |
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| 1110 | } |
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| 1111 | } |
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| 1112 | ||
| 1113 | return (is_nan($fBy)) ? Functions::NAN() : $fBy; |
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| 1114 | } |
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| 1115 | ||
| 1116 | return Functions::VALUE(); |
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| 1117 | } |
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| 1118 | ||
| 1119 | /** |
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| 1120 | * BINTODEC. |
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