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MDL-9643 evalmath library improvement - sample calc functions

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skodak
2007-05-25 06:07:45 +00:00
parent 61d9b9fc5d
commit 2d53fa5031
2 changed files with 103 additions and 23 deletions
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lib/evalmath/evalmath.class.php
+92 -23
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@@ -99,6 +99,9 @@ class EvalMath {
'cos','cosh','arccos','acos','arccosh','acosh',
'tan','tanh','arctan','atan','arctanh','atanh',
'sqrt','abs','ln','log');
var $fc = array( // calc functions emulation
'sum'=>array(-1), 'pi'=>array(0), 'power'=>array(2), 'round'=>array(2,1), 'average'=>array(-1));
function EvalMath() {
// make the variables a little more accurate
@@ -198,7 +201,8 @@ class EvalMath {
//===============
} elseif ((in_array($op, $ops) or $ex) and $expecting_op) { // are we putting an operator on the stack?
if ($ex) { // are we expecting an operator but have a number/variable/function/opening parethesis?
$op = '*'; $index--; // it's an implicit multiplication
return $this->trigger("expecting operand");
//$op = '*'; $index--; // it's an implicit multiplication
}
// heart of the algorithm:
while($stack->count > 0 and ($o2 = $stack->last()) and in_array($o2, $ops) and ($ops_r[$op] ? $ops_p[$op] < $ops_p[$o2] : $ops_p[$op] <= $ops_p[$o2])) {
@@ -217,10 +221,16 @@ class EvalMath {
if (preg_match("/^([a-z]\w*)\($/", $stack->last(2), $matches)) { // did we just close a function?
$fnn = $matches[1]; // get the function name
$arg_count = $stack->pop(); // see how many arguments there were (cleverly stored on the stack, thank you)
$output[] = $stack->pop(); // pop the function and push onto the output
$fn = $stack->pop();
$output[] = array('fn'=>$fn, 'fnn'=>$fnn, 'argcount'=>$arg_count); // send function to output
if (in_array($fnn, $this->fb)) { // check the argument count
if($arg_count > 1)
return $this->trigger("too many arguments ($arg_count given, 1 expected)");
} elseif (array_key_exists($fnn, $this->fc)) {
$counts = $this->fc[$fnn];
if (in_array(-1, $counts) and $arg_count > 0) {}
elseif (!in_array($arg_count, $counts))
return $this->trigger("wrong number of arguments ($arg_count given, " . implode('/',$this->fc[$fnn]) . " expected)");
} elseif (array_key_exists($fnn, $this->f)) {
if ($arg_count != count($this->f[$fnn]['args']))
return $this->trigger("wrong number of arguments ($arg_count given, " . count($this->f[$fnn]['args']) . " expected)");
@@ -252,7 +262,7 @@ class EvalMath {
$expecting_op = true;
$val = $match[1];
if (preg_match("/^([a-z]\w*)\($/", $val, $matches)) { // may be func, or variable w/ implicit multiplication against parentheses...
if (in_array($matches[1], $this->fb) or array_key_exists($matches[1], $this->f)) { // it's a func
if (in_array($matches[1], $this->fb) or array_key_exists($matches[1], $this->f) or array_key_exists($matches[1], $this->fc)) { // it's a func
$stack->push($val);
$stack->push(1);
$stack->push('(');
@@ -266,9 +276,24 @@ class EvalMath {
}
$index += strlen($val);
//===============
} elseif ($op == ')') { // miscellaneous error checking
return $this->trigger("unexpected ')'");
} elseif (in_array($op, $ops) and !$expecting_op) {
} elseif ($op == ')') {
//it could be only custom function with no params or general error
if ($stack->last() != '(' or $stack->last(2) != 1) return $this->trigger("unexpected ')'");
if (preg_match("/^([a-z]\w*)\($/", $stack->last(3), $matches)) { // did we just close a function?
$stack->pop();// (
$stack->pop();// 1
$fn = $stack->pop();
$fnn = $matches[1]; // get the function name
$counts = $this->fc[$fnn];
if (!in_array(0, $counts))
return $this->trigger("wrong number of arguments ($arg_count given, " . implode('/',$this->fc[$fnn]) . " expected)");
$output[] = array('fn'=>$fn, 'fnn'=>$fnn, 'argcount'=>0); // send function to output
$index++;
} else {
return $this->trigger("unexpected ')'");
}
//===============
} elseif (in_array($op, $ops) and !$expecting_op) { // miscellaneous error checking
return $this->trigger("unexpected operator '$op'");
} else { // I don't even want to know what you did to get here
return $this->trigger("an unexpected error occured");
@@ -300,8 +325,37 @@ class EvalMath {
$stack = new EvalMathStack;
foreach ($tokens as $token) { // nice and easy
// if the token is a function, pop arguments off the stack, hand them to the function, and push the result back on
if (is_array($token)) { // it's a function!
$fnn = $token['fnn'];
$count = $token['argcount'];
if (in_array($fnn, $this->fb)) { // built-in function:
if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
$fnn = preg_replace("/^arc/", "a", $fnn); // for the 'arc' trig synonyms
if ($fnn == 'ln') $fnn = 'log';
eval('$stack->push(' . $fnn . '($op1));'); // perfectly safe eval()
} elseif (array_key_exists($fnn, $this->fc)) { // calc emulation function
// get args
$args = array();
for ($i = $count-1; $i >= 0; $i--) {
if (is_null($args[] = $stack->pop())) return $this->trigger("internal error");
}
$res = call_user_func(array('EvalMathCalcEmul', $fnn), $args);
if ($res == FALSE) {
return $this->trigger("internal error");
}
$stack->push($res);
} elseif (array_key_exists($fnn, $this->f)) { // user function
// get args
$args = array();
for ($i = count($this->f[$fnn]['args'])-1; $i >= 0; $i--) {
if (is_null($args[$this->f[$fnn]['args'][$i]] = $stack->pop())) return $this->trigger("internal error");
}
$stack->push($this->pfx($this->f[$fnn]['func'], $args)); // yay... recursion!!!!
}
// if the token is a binary operator, pop two values off the stack, do the operation, and push the result back on
if (in_array($token, array('+', '-', '*', '/', '^'))) {
} elseif (in_array($token, array('+', '-', '*', '/', '^'), true)) {
if (is_null($op2 = $stack->pop())) return $this->trigger("internal error");
if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
switch ($token) {
@@ -320,22 +374,6 @@ class EvalMath {
// 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 function, pop arguments off the stack, hand them to the function, and push the result back on
} elseif (preg_match("/^([a-z]\w*)\($/", $token, $matches)) { // it's a function!
$fnn = $matches[1];
if (in_array($fnn, $this->fb)) { // built-in function:
if (is_null($op1 = $stack->pop())) return $this->trigger("internal error");
$fnn = preg_replace("/^arc/", "a", $fnn); // for the 'arc' trig synonyms
if ($fnn == 'ln') $fnn = 'log';
eval('$stack->push(' . $fnn . '($op1));'); // perfectly safe eval()
} elseif (array_key_exists($fnn, $this->f)) { // user function
// get args
$args = array();
for ($i = count($this->f[$fnn]['args'])-1; $i >= 0; $i--) {
if (is_null($args[$this->f[$fnn]['args'][$i]] = $stack->pop())) return $this->trigger("internal error");
}
$stack->push($this->pfx($this->f[$fnn]['func'], $args)); // yay... recursion!!!!
}
// if the token is a number or variable, push it on the stack
} else {
if (is_numeric($token)) {
@@ -386,3 +424,34 @@ class EvalMathStack {
}
}
// spreadsheed functions emulation
// watch out for reversed args!!
class EvalMathCalcEmul {
function average($args) {
return (EvalMathCalcEmul::sum($args)/count($args));
}
function pi($args) {
return pi();
}
function power($args) {
return $args[0]^$args[0];
}
function round($args) {
if (count($args)==1) {
return round($args[0]);
} else {
return round($args[1], $args[0]);
}
}
function sum($args) {
$res = 0;
foreach($args as $a) {
$res += $a;
}
return $res;
}
}