查找数组的所有局部最大值和最小值

in php we can determine global maximum and global minimum of a array , but what we do for finding local minimum(minima) and local maximum (maxima) .

how we can get all this point with php

It's remarkably simple for tabulated data.

Track along the ordinate values, and compute successive differences. You have a stationary point if the difference changes sign.

It's more difficult if you're attempting to apply an interpolation rule that can introduce turning points between knots, such as a cubic spline.