%PDF-
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Mini Shell
<?php
/**
* EvalMath - Safely evaluate math expressions
*
* Based on EvalMath by Miles Kaufmann, with modifications by Petr Skoda.
* @link https://github.com/moodle/moodle/blob/4efc3d4096bc1d29e9d77f9af7194b2babfa2821/lib/evalmath/evalmath.class.php
*
* @package TablePress
* @subpackage Formulas
* @author Miles Kaufmann, Petr Skoda, Tobias Bäthge
* @since 1.0.0
*/
// Prohibit direct script loading.
defined( 'ABSPATH' ) || die( 'No direct script access allowed!' );
/**
* Class to safely evaluate math expressions.
* @package TablePress
* @subpackage Formulas
* @since 1.0.0
*/
class EvalMath {
/**
* Pattern used for a valid function or variable name.
*
* Note, var and func names are case insensitive.
*
* @since 1.0.0
* @var string
*/
protected static $name_pattern = '[a-z][a-z0-9_]*';
/**
* Whether to suppress errors and warnings.
*
* @since 1.0.0
* @var boolean
*/
public $suppress_errors = false;
/**
* The last error message that was raised.
*
* @since 1.0.0
* @var string
*/
public $last_error = '';
/**
* Variables (including constants).
*
* @since 1.0.0
* @var array
*/
protected $variables = array();
/**
* User-defined functions.
*
* @since 1.0.0
* @var array
*/
protected $functions = array();
/**
* Constants.
*
* @since 1.0.0
* @var array
*/
protected $constants = array();
/**
* Built-in functions.
*
* @since 1.0.0
* @var array
*/
protected $builtin_functions = array(
'sin', 'sinh', 'arcsin', 'asin', 'arcsinh', 'asinh',
'cos', 'cosh', 'arccos', 'acos', 'arccosh', 'acosh',
'tan', 'tanh', 'arctan', 'atan', 'arctanh', 'atanh',
'sqrt', 'abs', 'ln', 'log10', 'exp', 'floor', 'ceil',
);
/**
* Emulated functions.
*
* @since 1.0.0
* @var array
*/
protected $calc_functions = array(
'average' => array( -1 ),
'mean' => array( -1 ),
'median' => array( -1 ),
'mode' => array( -1 ),
'range' => array( -1 ),
'max' => array( -1 ),
'min' => array( -1 ),
'mod' => array( 2 ),
'pi' => array( 0 ),
'power' => array( 2 ),
'log' => array( 1, 2 ),
'round' => array( 1, 2 ),
'number_format' => array( 1, 2 ),
'number_format_eu' => array( 1, 2 ),
'sum' => array( -1 ),
'product' => array( -1 ),
'rand_int' => array( 2 ),
'rand_float' => array( 0 ),
'arctan2' => array( 2 ),
'atan2' => array( 2 ),
'if' => array( 3 ),
'not' => array( 1 ),
'and' => array( -1 ),
'or' => array( -1 ),
);
/**
* Class constructor.
*
* @since 1.0.0
*/
public function __construct() {
// Sets default constants.
$this->variables['pi'] = pi();
$this->variables['e'] = exp( 1 );
}
/**
* Evaluate a math expression without checking it for variable or function assignments.
*
* @since 1.0.0
*
* @param string $expression The expression that shall be evaluated.
* @return string Evaluated expression.
*/
public function evaluate( $expression ) {
return $this->pfx( $this->nfx( $expression ) );
}
/**
* Evaluate a math expression or formula, and check it for variable an function assignments.
*
* @since 1.0.0
*
* @param string $expression The expression that shall be evaluated.
* @return string|bool Evaluated expression, true on successful function assignment, or false on error.
*/
public function assign_and_evaluate( $expression ) {
$this->last_error = '';
$expression = trim( $expression );
$expression = rtrim( $expression, ';' );
// Is the expression a variable assignment?
if ( 1 === preg_match( '/^\s*(' . self::$name_pattern . ')\s*=\s*(.+)$/', $expression, $matches ) ) {
// Make sure we're not assigning to a constant.
if ( in_array( $matches[1], $this->constants, true ) ) {
return $this->raise_error( 'cannot_assign_to_constant', $matches[1] );
}
// Evaluate the assignment.
$tmp = $this->pfx( $this->nfx( $matches[2] ) );
if ( fales === $tmp ) {
return false;
}
// If it could be evaluated, add it to the variable array,
$this->variables[ $matches[1] ] = $tmp;
// and return the resulting value.
return $tmp;
// Is the expression a function assignment?
} elseif ( 1 === preg_match( '/^\s*(' . self::$name_pattern . ')\s*\(\s*(' . self::$name_pattern . '(?:\s*,\s*' . self::$name_pattern . ')*)\s*\)\s*=\s*(.+)$/', $expression, $matches ) ) {
// Get the function name.
$function_name = $matches[1];
// Make sure it isn't a built-in function -- we can't redefine those.
if ( in_array( $matches[1], $this->builtin_functions, true ) ) {
return $this->raise_error( 'cannot_redefine_builtin_function', $matches[1] );
}
// Get the function arguments after removing all whitespace.
$matches[2] = str_replace( array( "\n", "\r", "\t", ' ' ), '', $matches[2] );
$args = explode( ',', $matches[2] );
// Convert the function definition to postfix notation.
$stack = $this->nfx( $matches[3] );
if ( false === $stack ) {
return false;
}
// Freeze the state of the non-argument variables.
for ( $i = 0; $i < count( $stack ); $i++ ) {
$token = $stack[ $i ];
if ( 1 === preg_match( '/^' . self::$name_pattern . '$/', $token ) && ! in_array( $token, $args, true ) ) {
if ( array_key_exists( $token, $this->variables ) ) {
$stack[ $i ] = $this->variables[ $token ];
} else {
return $this->raise_error( 'undefined_variable_in_function_definition', $token );
}
}
}
$this->functions[ $function_name ] = array( 'args' => $args, 'func' => $stack );
return true;
// No variable or function assignment, so straight-up evaluation.
} else {
return $this->evaluate( $expression );
}
}
/**
* Return all user-defined variables and values.
*
* @since 1.0.0
*
* @return array User-defined variables and values.
*/
public function variables() {
return $this->variables;
}
/**
* Return all user-defined functions with their arguments.
*
* @since 1.0.0
*
* @return array User-defined functions.
*/
public function functions() {
$output = array();
foreach ( $this->functions as $name => $data ) {
$output[] = $name . '( ' . implode( ', ', $data['args'] ) . ' )';
}
return $output;
}
/*
* Internal methods.
*/
/**
* Convert infix to postfix notation.
*
* @since 1.0.0
*
* @param string $expression Math expression that shall be converted.
* @return array|false Converted expression or false on error.
*/
protected function nfx( $expression ) {
$index = 0;
$stack = new EvalMath_Stack;
$output = array(); // postfix form of expression, to be passed to pfx()
$expression = trim( strtolower( $expression ) );
$ops = array( '+', '-', '*', '/', '^', '_', '>', '<', '=' );
// Right-associative operator?
$ops_r = array( '+' => 0, '-' => 0, '*' => 0, '/' => 0, '^' => 1, '>' => 0, '<' => 0, '=' => 0 );
// Operator precedence.
$ops_p = array( '+' => 0, '-' => 0, '*' => 1, '/' => 1, '_' => 1, '^' => 2, '>' => 0, '<' => 0, '=' => 0 );
// We use this in syntax-checking the expression and determining when a - (minus) is a negation.
$expecting_operator = false;
// Make sure the characters are all good.
if ( 1 === preg_match( '/[^\w\s+*^\/()\.,-<>=]/', $expression, $matches ) ) {
return $this->raise_error( 'illegal_character_general', $matches[0] );
}
// Infinite Loop for the conversion.
while ( true ) {
// Get the first character at the current index.
$op = substr( $expression, $index, 1 );
// Find out if we're currently at the beginning of a number/variable/function/parenthesis/operand.
$ex = preg_match( '/^(' . self::$name_pattern . '\(?|\d+(?:\.\d*)?(?:(e[+-]?)\d*)?|\.\d+|\()/', substr( $expression, $index ), $match );
// Is it a negation instead of a minus (in a subtraction)?
if ( '-' === $op && ! $expecting_operator ) {
// Put a negation on the stack.
$stack->push( '_' );
$index++;
} elseif ( '_' === $op ) {
// We have to explicitly deny underscores (as they mean negation), because they are legal on the stack.
return $this->raise_error( 'illegal_character_underscore' );
// Are we putting an operator on the stack?
} elseif ( ( in_array( $op, $ops, true ) || $ex ) && $expecting_operator ) {
// Are we expecting an operator but have a number/variable/function/opening parethesis?
if ( $ex ) {
// It's an implicit multiplication.
$op = '*';
$index--;
}
// Heart of the algorithm:
while ( $stack->count > 0 && ( $o2 = $stack->last() ) && in_array( $o2, $ops, true ) && ( $ops_r[ $op ] ? $ops_p[ $op ] < $ops_p[ $o2 ] : $ops_p[ $op ] <= $ops_p[ $o2 ] ) ) {
// Pop stuff off the stack into the output.
$output[] = $stack->pop();
}
// Many thanks: https://en.wikipedia.org/wiki/Reverse_Polish_notation
$stack->push( $op ); // finally put OUR operator onto the stack
$index++;
$expecting_operator = false;
// Ready to close a parenthesis?
} elseif ( ')' === $op && $expecting_operator ) {
// Pop off the stack back to the last (.
while ( '(' !== ( $o2 = $stack->pop() ) ) {
if ( is_null( $o2 ) ) {
return $this->raise_error( 'unexpected_closing_bracket' );
} else {
$output[] = $o2;
}
}
// Did we just close a function?
if ( 1 === preg_match( '/^(' . self::$name_pattern . ')\($/', $stack->last( 2 ), $matches ) ) {
// Get the function name.
$function_name = $matches[1];
// See how many arguments there were (cleverly stored on the stack, thank you).
$arg_count = $stack->pop();
$fn = $stack->pop();
// Send function to output.
$output[] = array( 'function_name' => $function_name, 'arg_count' => $arg_count );
// Check the argument count, depending on what type of function we have.
if ( in_array( $function_name, $this->builtin_functions, true ) ) {
// Built-in functions.
if ( $arg_count > 1 ) {
$error_data = array( 'expected' => 1, 'given' => $arg_count );
return $this->raise_error( 'wrong_number_of_arguments', $error_data );
}
} elseif ( array_key_exists( $function_name, $this->calc_functions ) ) {
// Calc-emulation functions.
$counts = $this->calc_functions[ $function_name ];
if ( in_array( -1, $counts, true ) && $arg_count > 0 ) {
// Everything is fine, we expected an indefinite number arguments and got some.
} elseif ( ! in_array( $arg_count, $counts, true ) ) {
$error_data = array( 'expected' => implode( '/', $this->calc_functions[ $function_name ] ), 'given' => $arg_count );
return $this->raise_error( 'wrong_number_of_arguments', $error_data );
}
} elseif ( array_key_exists( $function_name, $this->functions ) ) {
// User-defined functions.
if ( count( $this->functions[ $function_name ]['args'] ) !== $arg_count ) {
$error_data = array( 'expected' => count( $this->functions[ $function_name ]['args'] ), 'given' => $arg_count );
return $this->raise_error( 'wrong_number_of_arguments', $error_data );
}
} else {
// Did we somehow push a non-function on the stack? This should never happen.
return $this->raise_error( 'internal_error' );
}
}
$index++;
// Did we just finish a function argument?
} elseif ( ',' === $op && $expecting_operator ) {
while ( '(' !== ( $o2 = $stack->pop() ) ) {
if ( is_null( $o2 ) ) {
// Oops, never had a (.
return $this->raise_error( 'unexpected_comma' );
} else {
// Pop the argument expression stuff and push onto the output.
$output[] = $o2;
}
}
// Make sure there was a function.
if ( 0 === preg_match( '/^(' . self::$name_pattern . ')\($/', $stack->last( 2 ), $matches ) ) {
return $this->raise_error( 'unexpected_comma' );
}
// Increment the argument count.
$stack->push( $stack->pop() + 1 );
// Put the ( back on, we'll need to pop back to it again.
$stack->push( '(' );
$index++;
$expecting_operator = false;
} elseif ( '(' === $op && ! $expecting_operator ) {
$stack->push( '(' ); // That was easy.
$index++;
// Do we now have a function/variable/number?
} elseif ( $ex && ! $expecting_operator ) {
$expecting_operator = true;
$value = $match[1];
// May be a function, or variable with implicit multiplication against parentheses...
if ( 1 === preg_match( '/^(' . self::$name_pattern . ')\($/', $value, $matches ) ) {
// Is it a function?
if ( in_array( $matches[1], $this->builtin_functions, true ) || array_key_exists( $matches[1], $this->functions ) || array_key_exists( $matches[1], $this->calc_functions ) ) {
$stack->push( $value );
$stack->push( 1 );
$stack->push( '(' );
$expecting_operator = false;
// It's a variable with implicit multiplication.
} else {
$value = $matches[1];
$output[] = $value;
}
} else {
// It's a plain old variable or number.
$output[] = $value;
}
$index += strlen( $value );
} elseif ( ')' === $op ) {
// It could be only custom function with no arguments or a general error.
if ( '(' !== $stack->last() || 1 !== $stack->last( 2 ) ) {
return $this->raise_error( 'unexpected_closing_bracket' );
}
// Did we just close a function?
if ( 1 === preg_match( '/^(' . self::$name_pattern . ')\($/', $stack->last( 3 ), $matches ) ) {
$stack->pop(); // (
$stack->pop(); // 1
$fn = $stack->pop();
// Get the function name.
$function_name = $matches[1];
if ( isset( $this->calc_functions[ $function_name ] ) ) {
// Custom calc-emulation function.
$counts = $this->calc_functions[ $function_name ];
} else {
// Default count for built-in functions.
$counts = array( 1 );
}
if ( ! in_array( 0, $counts, true ) ) {
$error_data = array( 'expected' => $counts, 'given' => 0 );
return $this->raise_error( 'wrong_number_of_arguments', $error_data );
}
// Send function to output.
$output[] = array( 'function_name' => $function_name, 'arg_count' => 0 );
$index++;
$expecting_operator = true;
} else {
return $this->raise_error( 'unexpected_closing_bracket' );
}
// Miscellaneous error checking.
} elseif ( in_array( $op, $ops, true ) && ! $expecting_operator ) {
return $this->raise_error( 'unexpected_operator', $op );
// I don't even want to know what you did to get here.
} else {
return $this->raise_error( 'an_unexpected_error_occurred' );
}
if ( strlen( $expression ) === $index ) {
// Did we end with an operator? Bad.
if ( in_array( $op, $ops, true ) ) {
return $this->raise_error( 'operator_lacks_operand', $op );
} else {
break;
}
}
// Step the index past whitespace (pretty much turns whitespace into implicit multiplication if no operator is there).
while ( ' ' === substr( $expression, $index, 1 ) ) {
$index++;
}
} // while ( true )
// Pop everything off the stack and push onto output.
while ( ! is_null( $op = $stack->pop() ) ) {
if ( '(' === $op ) {
// If there are (s on the stack, ()s were unbalanced.
return $this->raise_error( 'expecting_a_closing_bracket' );
}
$output[] = $op;
}
return $output;
}
/**
* Evaluate postfix notation.
*
* @since 1.0.0
*
* @param array|false $tokens [description]
* @param array $variables Optional. [description]
* @return mixed [description]
*/
protected function pfx( $tokens, array $variables = array() ) {
if ( false === $tokens ) {
return false;
}
$stack = new EvalMath_Stack;
foreach ( $tokens as $token ) {
// If the token is a function, pop arguments off the stack, hand them to the function, and push the result back on.
if ( is_array( $token ) ) { // it's a function!
$function_name = $token['function_name'];
$count = $token['arg_count'];
// Built-in function.
if ( in_array( $function_name, $this->builtin_functions, true ) ) {
$op1 = $stack->pop();
if ( is_null( $op1 ) ) {
return $this->raise_error( 'internal_error' );
}
// For the "arc" trigonometric synonyms.
$function_name = preg_replace( '/^arc/', 'a', $function_name );
// Rewrite "ln" (only allows one argument) to "log" (natural logarithm).
if ( 'ln' === $function_name ) {
$function_name = 'log';
}
// Perfectly safe eval().
eval( '$stack->push( ' . $function_name . '( $op1 ) );' );
// Calc-emulation function.
} elseif ( array_key_exists( $function_name, $this->calc_functions ) ) {
// Get function arguments.
$args = array();
for ( $i = $count - 1; $i >= 0; $i-- ) {
$arg = $stack->pop();
if ( is_null( $arg ) ) {
return $this->raise_error( 'internal_error' );
} else {
$args[] = $arg;
}
}
// Rewrite some functions to their synonyms.
if ( 'if' === $function_name ) {
$function_name = 'func_if';
} elseif ( 'not' === $function_name ) {
$function_name = 'func_not';
} elseif ( 'and' === $function_name ) {
$function_name = 'func_and';
} elseif ( 'or' === $function_name ) {
$function_name = 'func_or';
} elseif ( 'mean' === $function_name ) {
$function_name = 'average';
} elseif ( 'arctan2' === $function_name ) {
$function_name = 'atan2';
}
$result = call_user_func_array( array( 'EvalMath_Functions', $function_name ), array_reverse( $args ) );
if ( false === $result ) {
return $this->raise_error( 'internal_error' );
}
$stack->push( $result );
// User-defined function.
} elseif ( array_key_exists( $function_name, $this->functions ) ) {
// Get function arguments.
$args = array();
for ( $i = count( $this->functions[ $function_name ]['args'] ) - 1; $i >= 0; $i-- ) {
$arg = $stack->pop();
if ( is_null( $arg ) ) {
return $this->raise_error( 'internal_error' );
} else {
$args[ $this->functions[ $function_name ]['args'][ $i ] ] = $arg;
}
}
// yay... recursion!
$stack->push( $this->pfx( $this->functions[ $function_name ]['func'], $args ) );
}
// If the token is a binary operator, pop two values off the stack, do the operation, and push the result back on.
} elseif ( in_array( $token, array( '+', '-', '*', '/', '^', '>', '<', '=' ), true ) ) {
$op2 = $stack->pop();
if ( is_null( $op2 ) ) {
return $this->raise_error( 'internal_error' );
}
$op1 = $stack->pop();
if ( is_null( $op1 ) ) {
return $this->raise_error( 'internal_error' );
}
switch ( $token ) {
case '+':
$stack->push( $op1 + $op2 );
break;
case '-':
$stack->push( $op1 - $op2 );
break;
case '*':
$stack->push( $op1 * $op2 );
break;
case '/':
if ( 0 === $op2 || '0' === $op2 ) {
return $this->raise_error( 'division_by_zero' );
}
$stack->push( $op1 / $op2 );
break;
case '^':
$stack->push( pow( $op1, $op2 ) );
break;
case '>':
$stack->push( (int) ( $op1 > $op2 ) );
break;
case '<':
$stack->push( (int) ( $op1 < $op2 ) );
break;
case '=':
$stack->push( (int) ( $op1 == $op2 ) ); // Don't use === as the variable type can differ (int/double/bool).
break;
}
// If the token is a unary operator, pop one value off the stack, do the operation, and push it back on.
} elseif ( '_' === $token ) {
$stack->push( -1 * $stack->pop() );
// If the token is a number or variable, push it on the stack.
} else {
if ( is_numeric( $token ) ) {
$stack->push( $token );
} elseif ( array_key_exists( $token, $this->variables ) ) {
$stack->push( $this->variables[ $token ] );
} elseif ( array_key_exists( $token, $variables ) ) {
$stack->push( $variables[ $token ] );
} else {
return $this->raise_error( 'undefined_variable', $token );
}
}
}
// When we're out of tokens, the stack should have a single element, the final result.
if ( 1 !== $stack->count ) {
return $this->raise_error( 'internal_error' );
}
return $stack->pop();
}
/**
* Raise an error.
*
* @since 1.0.0
*
* @param string $message Error message.
* @param array|string $error_data Optional. Additional error data.
* @return bool False, to stop evaluation.
*/
protected function raise_error( $message, $error_data = null ) {
$this->last_error = $this->get_error_string( $message, $error_data );
return false;
}
/**
* Get a translated string for an error message.
*
* @since 1.0.0
*
* @link https://github.com/moodle/moodle/blob/13264f35057d2f37374ec3e0e8ad4070f4676bd7/lang/en/mathslib.php
* @link https://github.com/moodle/moodle/blob/8e54ce9717c19f768b95f4332f70e3180ffafc46/lib/moodlelib.php#L6323
*
* @param string $identifier Identifier of the string.
* @param array|string $error_data Optional. Additional error data.
* @return string Translated string.
*/
protected function get_error_string( $identifier, $error_data = null ) {
$strings = array();
$strings['an_unexpected_error_occurred'] = 'an unexpected error occurred';
$strings['cannot_assign_to_constant'] = 'cannot assign to constant \'{$error_data}\'';
$strings['cannot_redefine_builtin_function'] = 'cannot redefine built-in function \'{$error_data}()\'';
$strings['division_by_zero'] = 'division by zero';
$strings['expecting_a_closing_bracket'] = 'expecting a closing bracket';
$strings['illegal_character_general'] = 'illegal character \'{$error_data}\'';
$strings['illegal_character_underscore'] = 'illegal character \'_\'';
$strings['internal_error'] = 'internal error';
$strings['operator_lacks_operand'] = 'operator \'{$error_data}\' lacks operand';
$strings['undefined_variable'] = 'undefined variable \'{$error_data}\'';
$strings['undefined_variable_in_function_definition'] = 'undefined variable \'{$error_data}\' in function definition';
$strings['unexpected_closing_bracket'] = 'unexpected closing bracket';
$strings['unexpected_comma'] = 'unexpected comma';
$strings['unexpected_operator'] = 'unexpected operator \'{$error_data}\'';
$strings['wrong_number_of_arguments'] = 'wrong number of arguments ({$error_data->given} given, {$error_data->expected} expected)';
$string = $strings[ $identifier ];
if ( null !== $error_data ) {
if ( is_array( $error_data ) ) {
$search = array();
$replace = array();
foreach ( $error_data as $key => $value ) {
if ( is_int( $key ) ) {
// We do not support numeric keys!
continue;
}
if ( is_object( $value ) || is_array( $value ) ) {
$value = (array) $value;
if ( count( $value ) > 1 ) {
$value = implode( ' or ', $value );
} else {
$value = (string) $value[0];
if ( '-1' === $value ) {
$value = 'at least 1';
}
}
}
$search[] = '{$error_data->' . $key . '}';
$replace[] = (string) $value;
}
if ( $search ) {
$string = str_replace( $search, $replace, $string );
}
} else {
$string = str_replace( '{$error_data}', (string) $error_data, $string );
}
}
return $string;
}
} // class EvalMath
/**
* Stack for the postfix/infix conversion of math expressions.
* @package TablePress
* @subpackage Formulas
* @since 1.0.0
*/
class EvalMath_Stack {
/**
* The stack.
*
* @since 1.0.0
* @var array
*/
protected $stack = array();
/**
* Number of items on the stack.
*
* @since 1.0.0
* @var int
*/
public $count = 0;
/**
* Push an item onto the stack.
*
* @since 1.0.0
*
* @param mixed $value The item that is pushed onto the stack.
*/
public function push( $value ) {
$this->stack[ $this->count ] = $value;
$this->count++;
}
/**
* Pop an item from the top of the stack.
*
* @since 1.0.0
*
* @return mixed The item that is popped from the stack.
*/
public function pop() {
if ( $this->count > 0 ) {
$this->count--;
return $this->stack[ $this->count ];
}
return null;
}
/**
* Pop an item from the end of the stack.
*
* @since 1.0.0
*
* @param int $n Count from the end of the stack.
* @return mixed The item that is popped from the stack.
*/
public function last( $n = 1 ) {
if ( ( $this->count - $n ) >= 0 ) {
return $this->stack[ $this->count - $n ];
}
return null;
}
} // class EvalMath_Stack
/**
* Common math functions, prepared for usage in EvalMath.
* @package TablePress
* @subpackage EvalMath
* @since 1.0.0
*/
class EvalMath_Functions {
/**
* Seed for the generation of random numbers.
*
* @since 1.0.0
* @var string
*/
protected static $random_seed = null;
/**
* Choose from two values based on an if-condition.
*
* "if" is not a valid function name, which is why it's prefixed with "func_".
*
* @since 1.0.0
*
* @param double|int $condition Condition.
* @param double|int $then Return value if the condition is true.
* @param double|int $else Return value if the condition is false.
* @return double|int Result of the if check.
*/
public static function func_if( $condition, $then, $else ) {
return ( (bool) $condition ? $then : $else );
}
/**
* Return the negation (boolean "not") of a value.
*
* Similar to "func_if", the function name is prefixed with "func_", although it wouldn't be necessary.
*
* @since 1.0.0
*
* @param double|int $value Value to be negated.
* @return int Negated value (0 for false, 1 for true).
*/
public static function func_not( $value ) {
return (int) ! (bool) $value;
}
/**
* Calculate the conjunction (boolean "and") of some values.
*
* "and" is not a valid function name, which is why it's prefixed with "func_".
*
* @since 1.0.0
*
* @param double|int $args Values for which the conjunction shall be calculated.
* @return int Conjunction of the passed arguments.
*/
public static function func_and( $args ) {
$args = func_get_args();
foreach ( $args as $value ) {
if ( ! $value ) {
return 0;
}
}
return 1;
}
/**
* Calculate the disjunction (boolean "or") of some values.
*
* "or" is not a valid function name, which is why it's prefixed with "func_".
*
* @since 1.0.0
*
* @param double|int $args Values for which the disjunction shall be calculated.
* @return int Disjunction of the passed arguments.
*/
public static function func_or( $args ) {
$args = func_get_args();
foreach ( $args as $value ) {
if ( $value ) {
return 1;
}
}
return 0;
}
/**
* Return the (rounded) value of Pi.
*
* @since 1.0.0
*
* @return double Rounded value of Pi.
*/
public static function pi() {
return pi();
}
/**
* Calculate the sum of the arguments.
*
* @since 1.0.0
*
* @param double|int $args Values for which the sum shall be calculated.
* @return double|int Sum of the passed arguments.
*/
public static function sum( $args ) {
$args = func_get_args();
return array_sum( $args );
}
/**
* Calculate the product of the arguments.
*
* @since 1.0.0
*
* @param double|int $args Values for which the product shall be calculated.
* @return double|int Product of the passed arguments.
*/
public static function product( $args ) {
$args = func_get_args();
return array_product( $args );
}
/**
* Calculate the average/mean value of the arguments.
*
* @since 1.0.0
*
* @param double|int $args Values for which the average shall be calculated.
* @return double|int Average value of the passed arguments.
*/
public static function average( $args ) {
$args = func_get_args();
return ( call_user_func_array( array( 'self', 'sum' ), $args ) / count( $args ) );
}
/**
* Calculate the median of the arguments.
*
* For even counts of arguments, the upper median is returned.
*
* @since 1.0.0
*
* @param double|int $args Values for which the median shall be calculated.
* @return double|int Median of the passed arguments.
*/
public static function median( $args ) {
$args = func_get_args();
sort( $args );
$middle = floor( count( $args ) / 2 ); // Upper median for even counts.
return $args[ $middle ];
}
/**
* Calculate the mode of the arguments.
*
* @since 1.0.0
*
* @param double|int $args Values for which the mode shall be calculated.
* @return double|int Mode of the passed arguments.
*/
public static function mode( $args ) {
$args = func_get_args();
$values = array_count_values( $args );
asort( $values );
end( $values );
return key( $values );
}
/**
* Calculate the range of the arguments.
*
* @since 1.0.0
*
* @param double|int $args Values for which the range shall be calculated.
* @return double|int Range of the passed arguments.
*/
public static function range( $args ) {
$args = func_get_args();
sort( $args );
return end( $args ) - reset( $args );
}
/**
* Find the maximum value of the arguments.
*
* @since 1.0.0
*
* @param double|int $args Values for which the maximum value shall be found.
* @return double|int Maximum value of the passed arguments.
*/
public static function max( $args ) {
$args = func_get_args();
return max( $args );
}
/**
* Find the minimum value of the arguments.
*
* @since 1.0.0
*
* @param double|int $args Values for which the minimum value shall be found.
* @return double|int Minimum value of the passed arguments.
*/
public static function min( $args ) {
$args = func_get_args();
return min( $args );
}
/**
* Calculate the remainder of a division of two numbers.
*
* @since 1.0.0
*
* @param double|int $op1 First number (dividend).
* @param double|int $op2 Second number (divisor).
* @return double|int Remainer of the division (dividend / divisor).
*/
public static function mod( $op1, $op2 ) {
return $op1 % $op2;
}
/**
* Calculate the power of a base and an exponent.
*
* @since 1.0.0
*
* @param double|int $base Base.
* @param double|int $exponent Exponent.
* @return double|int Power base^exponent.
*/
public static function power( $base, $exponent ) {
return pow( $base, $exponent );
}
/**
* Calculate the logarithm of a number to a base.
*
* @since 1.0.0
*
* @param double|int $number Number.
* @param double|int $base Optional. Base for the logarithm. Default e (for the natural logarithm).
* @return double Logarithm of the number to the base.
*/
public static function log( $number, $base = M_E ) {
return log( $number, $base );
}
/**
* Calculate the arc tangent of two variables.
*
* The signs of the numbers determine the quadrant of the result.
*
* @since 1.0.0
*
* @param double|int $op1 First number.
* @param double|int $op2 Second number.
* @return double Arc tangent of two numbers, similar to arc tangent of $op1/op$ except for the sign.
*/
public static function atan2( $op1, $op2 ) {
return atan2( $op1, $op2 );
}
/**
* Round a number to a given precision.
*
* @since 1.0.0
*
* @param double|int $value Number to be rounded.
* @param double|int $decimals Optional. Number of decimals after the comma after the rounding.
* @return double Rounded number.
*/
public static function round( $value, $decimals = 0 ) {
return round( $value, $decimals );
}
/**
* Format a number with the . as the decimal separator and the , as the thousand separator, rounded to a precision.
*
* The is the common number format in English-language regions.
*
* @since 1.0.0
*
* @param double|int $value Number to be rounded and formatted.
* @param double|int $decimals Optional. Number of decimals after the decimal separator after the rounding.
* @return double Formatted number.
*/
public static function number_format( $value, $decimals = 0 ) {
return number_format( $value, $decimals, '.', ',' );
}
/**
* Format a number with the , as the decimal separator and the space as the thousand separator, rounded to a precision.
*
* The is the common number format in non-English-language regions, mainly in Europe.
*
* @since 1.0.0
*
* @param double|int $value Number to be rounded and formatted.
* @param double|int $decimals Optional. Number of decimals after the decimal separator after the rounding.
* @return double Formatted number.
*/
public static function number_format_eu( $value, $decimals = 0 ) {
return number_format( $value, $decimals, ',', ' ' );
}
/**
* Set the seed for the generation of random numbers.
*
* @since 1.0.0
*
* @param string The seed.
*/
protected static function _set_random_seed( $random_seed ) {
self::$random_seed = $random_seed;
}
/**
* Get the seed for the generation of random numbers.
*
* @since 1.0.0
*
* @return string The seed.
*/
protected static function _get_random_seed() {
if ( is_null( self::$random_seed ) ) {
return microtime();
} else {
return self::$random_seed;
}
}
/**
* Get a random integer from a range.
*
* @since 1.0.0
*
* @param int $min Minimum value for the range.
* @param int $max Maximum value for the range.
* @return int Random integer from the range [$min, $max].
*/
public static function rand_int( $min, $max ) {
// Swap min and max value if min is bigger than max.
if ( $min > $max ) {
$tmp = $max;
$max = $min;
$min = $tmp;
unset( $tmp );
}
$number_characters = ceil( log( $max + 1 - $min, '16' ) );
$md5string = md5( self::_get_random_seed() );
$offset = 0;
do {
while ( ( $offset + $number_characters ) > strlen( $md5string ) ) {
$md5string .= md5( $md5string );
}
$randomno = hexdec( substr( $md5string, $offset, $number_characters ) );
$offset += $number_characters;
} while ( ( $min + $randomno ) > $max );
return $min + $randomno;
}
/**
* Get a random double value from a range [0, 1].
*
* @since 1.0.0
*
* @return double Random number from the range [0, 1].
*/
public static function rand_float() {
$random_values = unpack( 'v', md5( self::_get_random_seed(), true ) );
return array_shift( $random_values ) / 65536;
}
} // class EvalMath_Functions
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