##### numpy 寻找极值 ```python np.maximum(x1, x2, /[, out, where, casting, ...]) # 比较数组元素最大值 [ufunc] np.max(a[, axis, out, keepdims, initial, where]) # 数组或指定轴上的最大值 np.amax(a[, axis, out, keepdims, initial, where]) # 数组或指定轴上的最大值 np.fmax(x1, x2, /[, out, where, casting, ...]) # 比较数组元素最大值 [ufunc] np.nanmax(a[, axis, out, keepdims, initial, where]) # 数组或指定轴上的最大值，忽略 NaN 值 np.minimum(x1, x2, /[, out, where, casting, ...]) # 比较数组元素最小值 [ufunc] np.min(a[, axis, out, keepdims, initial, where]) # 数组或指定轴上的最小值 np.amin(a[, axis, out, keepdims, initial, where]) # 数组或指定轴上的最小值 np.fmin(x1, x2, /[, out, where, casting, ...]) # 比较数组元素最小值 [ufunc] np.nanmin(a[, axis, out, keepdims, initial, where]) # 数组或指定轴上的最小值，忽略 NaN 值 ```