Indexing functions

These functions allow to retrieve or modify array elements indexed by either integral arrays of indices or boolean mask arrays.

extract(condition, arr)	Returns the elements of an array that satisfies the condition.
place(arr, mask, vals)	Change elements of an array based on conditional and input values.
put(x, indices, vals[, axis, mode])	Puts values into an array along a given axis at given indices.
take(x, indices[, axis, mode])	Takes elements from an array along a given axis at given indices.