PHP 代码:PHP 写的求多项式导数的函数代码
PHP 写的求多项式导数的函数代码,需要的朋友可以参考下
代码如下
:
<?php
function
getDerivativeByFormulaAndXDATA(
$formula
,
$x_data
){
$xArray
=
explode
("+",
$formula
);
$Derivative
= 0;
foreach
(
$xArray
as
$x_record
) {
$tmpArray
=
explode
("x^",
$x_record
);
if
(
count
(
$tmpArray
) == 2){
$coefficient
=
$tmpArray
[0]==""?1:
$tmpArray
[0];
$exp
=
$tmpArray
[1];
}
//constant
else
{
$coefficient
=
$tmpArray
[0];
$exp
= 0;
}
$Derivative
+=
$coefficient
*
$exp
*pow(
$x_data
,
$exp
-1);
}
return
$Derivative
;
}
function
getValueByFormulaAndXDATA(
$formula
,
$x_data
){
$xArray
=
explode
("+",
$formula
);
$y_data
= 0;
foreach
(
$xArray
as
$x_record
) {
$tmpArray
=
explode
("x^",
$x_record
);
if
(
count
(
$tmpArray
) == 2){
$coefficient
=
$tmpArray
[0]==""?1:
$tmpArray
[0];
$exp
=
$tmpArray
[1];
}
//constant
else
{
$coefficient
=
$tmpArray
[0];
$exp
= 0;
}
$y_data
+=
$coefficient
*pow(
$x_data
,
$exp
);
}
return
$y_data
;