php rounded to the nearest degree time with ms calculator
For people interest in Differential Equations, I've done a function that receive a string like: x^2+x^3 and put it in 2x+3x^2 witch is the differantial of the previous equation. In the code there is one thing missing: the $string{$i} is often going outOfBound (Uninitialized string offset: 6 in...) if your error setting is set a little too high... I just dont know how to fix this. So there is the code for differential equation with (+ and -) only: <? function differentiel($equa) { $equa = strtolower($equa); echo "Equation de depart: ".$equa."<br>"; $final = ""; for($i = 0; $i < strlen($equa); $i++) { //Make a new string from the receive $equa if($equa{$i} == "x" && $equa{$i+1} == "^") { $final .= $equa{$i+2}; $final .= "x^"; $final .= $equa{$i+2}-1; } elseif($equa{$i} == "+" || $equa{$i} == "-") { $final .= $equa{$i}; } elseif(is_numeric($equa{$i}) && $i == 0) { //gerer parenthese et autre terme generaux + gerer ^apres: 2^2 $final .= $equa{$i}."*"; } elseif(is_numeric($equa{$i}) && $i > 0 && $equa{$i-1} != "^") { //gerer ^apres: 2^2 $final .= $equa{$i}."*"; } elseif($equa{$i} == "^") { continue; } elseif(is_numeric($equa{$i}) && $equa{$i-1} == "^") { continue; } else { if($equa{$i} == "x") { $final .= 1; } else { $final .= $equa{$i}; } } } // //Manage multiplication add in the previous string $final // $finalMul = ""; for($i = 0; $i < strlen($final); $i++) { if(is_numeric($final{$i}) && $final{$i+1} == "*" && is_numeric($final{$i+2})) { $finalMul .= $final{$i}*$final{$i+2}; } elseif($final{$i} == "*") { continue; } elseif(is_numeric($final{$i}) && $final{$i+1} != "*" && $final{$i-1} == "*") { continue; } else { $finalMul .= $final{$i}; } } echo "equa final: ".$finalMul; } ?> I know this is not optimal but i've done this quick :) If you guys have any comment just email me. I also want to do this fonction In C to add to phpCore maybe soon... Patoff