ILIAS  release_8 Revision v8.24
Public Member Functions | Protected Member Functions
ilMathBaseAdapter Class Reference

This file is part of ILIAS, a powerful learning management system published by ILIAS open source e-Learning e.V. More...

+ Inheritance diagram for ilMathBaseAdapter:
+ Collaboration diagram for ilMathBaseAdapter:

Public Member Functions

 applyScale ($left_operand, int $scale=null)
 @inheritDoc More...
 
 round ($value, int $precision=0)
 @inheritDoc More...
 
 equals ($left_operand, $right_operand, int $scale=null)
 @inheritDoc More...
 
- Public Member Functions inherited from ilMathAdapter
 add ($left_operand, $right_operand, int $scale=null)
 Adds two numbers. More...
 
 sub ($left_operand, $right_operand, int $scale=null)
 Subtracts two numbers. More...
 
 mul ($left_operand, $right_operand, int $scale=null)
 Multiplies two numbers. More...
 
 div ($left_operand, $right_operand, int $scale=null)
 Divides two numbers. More...
 
 mod ($left_operand, $right_operand)
 Gets modulus of two numbers. More...
 
 pow ($left_operand, $right_operand, int $scale=null)
 Raises a number to another. More...
 
 sqrt ($operand, int $scale=null)
 Gets the square root of a number. More...
 
 comp ($left_operand, $right_operand, int $scale=null)
 Compares two numbers. More...
 
 equals ($left_operand, $right_operand, int $scale=null)
 Checks whether or not two numbers are identical. More...
 
 applyScale ($left_operand, int $scale=null)
 This method adapts the behaviour of bcscale() More...
 
 round ($value, int $precision=0)
 

Protected Member Functions

 normalize ($number)
 This function fixes problems which occur when locale ist set to de_DE for example, because bc* function expecting strings. More...
 
 exp2dec ($float_str)
 

Detailed Description

This file is part of ILIAS, a powerful learning management system published by ILIAS open source e-Learning e.V.

ILIAS is licensed with the GPL-3.0, see https://www.gnu.org/licenses/gpl-3.0.en.html You should have received a copy of said license along with the source code, too.

If this is not the case or you just want to try ILIAS, you'll find us at: https://www.ilias.de https://github.com/ILIAS-eLearning Class ilMathBaseAdapter

Author
Michael Jansen mjans.nosp@m.en@d.nosp@m.ataba.nosp@m.y.de

Definition at line 23 of file class.ilMathBaseAdapter.php.

Member Function Documentation

◆ applyScale()

ilMathBaseAdapter::applyScale (   $left_operand,
int  $scale = null 
)

@inheritDoc

Implements ilMathAdapter.

Definition at line 28 of file class.ilMathBaseAdapter.php.

28 : string
29 {
30 if (is_numeric($left_operand)) {
31 $scale = (int) $scale;
32
33 $left_operand = $this->exp2dec($left_operand);
34 if (strpos($left_operand, '.') === false) {
35 $number_of_decimals = 0;
36 } else {
37 $number_of_decimals = strlen(substr($left_operand, strpos($left_operand, '.') + 1));
38 }
39
40 if ($number_of_decimals > 0 && $number_of_decimals < $scale) {
41 $left_operand = str_pad($left_operand, $scale - $number_of_decimals, '0');
42 } elseif ($number_of_decimals > $scale) {
43 $left_operand = substr($left_operand, 0, -($number_of_decimals - $scale));
44 }
45 }
46
47 return $left_operand;
48 }

References exp2dec(), and ILIAS\Repository\int().

Referenced by ilMathPhpAdapter\add(), ilMathPhpAdapter\comp(), ilMathPhpAdapter\div(), ilMathPhpAdapter\mul(), ilMathBCMathAdapter\pow(), ilMathPhpAdapter\pow(), ilMathPhpAdapter\sqrt(), and ilMathPhpAdapter\sub().

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◆ equals()

ilMathBaseAdapter::equals (   $left_operand,
  $right_operand,
int  $scale = null 
)

@inheritDoc

Implements ilMathAdapter.

Definition at line 61 of file class.ilMathBaseAdapter.php.

61 : bool
62 {
63 return $this->comp($left_operand, $right_operand, $scale) === 0;
64 }
ilMathAdapter\comp
comp($left_operand, $right_operand, int $scale=null)
Compares two numbers.

References ilMathAdapter\comp().

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◆ exp2dec()

ilMathBaseAdapter::exp2dec (   $float_str)
protected
Parameters
float | string | int$float_str
Returns
string

Definition at line 101 of file class.ilMathBaseAdapter.php.

101 : string
102 {
103 // make sure its a standard php float string (i.e. change 0.2e+2 to 20)
104 // php will automatically format floats decimally if they are within a certain range
105 $original = $float_str; // store original float, so we can return a float keeping the pecision when possible
106 $float_str = (string) ((float) ($float_str));
107 $float_str = str_replace(",", ".", $float_str); // convert ',' to '.' (float casting was locale sensitive)
108
109 // if there is an E in the float string
110 if (($pos = stripos($float_str, 'e')) !== false) {
111 // get either side of the E, e.g. 1.6E+6 => exp E+6, num 1.6
112 $exp = substr($float_str, $pos + 1);
113 $num = substr($float_str, 0, $pos);
114
115 // strip off num sign, if there is one, and leave it off if its + (not required)
116 if ((($num_sign = $num[0]) === '+') || ($num_sign === '-')) {
117 $num = substr($num, 1);
118 } else {
119 $num_sign = '';
120 }
121 if ($num_sign === '+') {
122 $num_sign = '';
123 }
124
125 // strip off exponential sign ('+' or '-' as in 'E+6') if there is one, otherwise throw error, e.g. E+6 => '+'
126 if ((($exp_sign = $exp[0]) === '+') || ($exp_sign === '-')) {
127 $exp = substr($exp, 1);
128 } else {
129 trigger_error("Could not convert exponential notation to decimal notation: invalid float string '$float_str'", E_USER_ERROR);
130 }
131
132 // get the number of decimal places to the right of the decimal point (or 0 if there is no dec point), e.g., 1.6 => 1
133 $right_dec_places = (($dec_pos = strpos($num, '.')) === false) ? 0 : strlen(substr($num, $dec_pos + 1));
134 // get the number of decimal places to the left of the decimal point (or the length of the entire num if there is no dec point), e.g. 1.6 => 1
135 $left_dec_places = ($dec_pos === false) ? strlen($num) : strlen(substr($num, 0, $dec_pos));
136
137 // work out number of zeros from exp, exp sign and dec places, e.g. exp 6, exp sign +, dec places 1 => num zeros 5
138 if ($exp_sign === '+') {
139 $num_zeros = $exp - $right_dec_places;
140 } else {
141 $num_zeros = $exp - $left_dec_places;
142 }
143
144 // build a string with $num_zeros zeros, e.g. '0' 5 times => '00000'
145 $zeros = str_pad('', $num_zeros, '0');
146
147 // strip decimal from num, e.g. 1.6 => 16
148 if ($dec_pos !== false) {
149 $num = str_replace('.', '', $num);
150 }
151
152 // if positive exponent, return like 1600000
153 if ($exp_sign === '+') {
154 return $num_sign . $num . $zeros;
155 }
156
157 // if negative exponent, return like 0.0000016
158 return $num_sign . '0.' . $zeros . $num;
159 }
160
161 // otherwise, assume already in decimal notation and return
162 return $original;
163 }

Referenced by applyScale(), normalize(), and ilMathBCMathAdapter\pow().

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◆ normalize()

ilMathBaseAdapter::normalize (   $number)
protected

This function fixes problems which occur when locale ist set to de_DE for example, because bc* function expecting strings.

Parameters
mixed$number
Returns
string

Definition at line 72 of file class.ilMathBaseAdapter.php.

72 : ?string
73 {
74 if (null === $number) {
75 return null;
76 }
77
78 $number = trim((string) $number);
79 $number = $this->exp2dec($number);
80 $locale_info = localeconv();
81
82 if ($locale_info['decimal_point'] !== '.') {
83 $append = '';
84 $number_of_decimals = (int) ini_get('precision') - (int) floor(log10(abs($number)));
85 if (0 > $number_of_decimals) {
86 $number *= 10 ** $number_of_decimals;
87 $append = str_repeat('0', -$number_of_decimals);
88 $number_of_decimals = 0;
89 }
90
91 return number_format($number, $number_of_decimals, '.', '') . $append;
92 }
93
94 return $number;
95 }

References exp2dec(), and ILIAS\Repository\int().

Referenced by ilMathBCMathAdapter\add(), ilMathPhpAdapter\add(), ilMathPhpAdapter\comp(), ilMathBCMathAdapter\div(), ilMathPhpAdapter\div(), ilMathBCMathAdapter\mod(), ilMathPhpAdapter\mod(), ilMathBCMathAdapter\mul(), ilMathPhpAdapter\mul(), ilMathBCMathAdapter\pow(), ilMathPhpAdapter\pow(), ilMathPhpAdapter\sqrt(), ilMathBCMathAdapter\sub(), and ilMathPhpAdapter\sub().

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◆ round()

ilMathBaseAdapter::round (   $value,
int  $precision = 0 
)

@inheritDoc

Implements ilMathAdapter.

Definition at line 53 of file class.ilMathBaseAdapter.php.

53 : string
54 {
55 return number_format($value, $precision, '.', '');
56 }
The documentation for this class was generated from the following file: