Return the floor of the input, element-wise.
The floor of the scalar x is the largest integer i, such that
i <= x.  It is often denoted as 
.
| Parameters : | x : array_like 
  | 
|---|---|
| Returns : | y : {ndarray, scalar} 
  | 
Notes
Some spreadsheet programs calculate the “floor-towards-zero”, in other words floor(-2.5) == -2. NumPy, however, uses the a definition of floor such that floor(-2.5) == -3.
Examples
>>> a = np.array([-1.7, -1.5, -0.2, 0.2, 1.5, 1.7, 2.0])
>>> np.floor(a)
array([-2., -2., -1.,  0.,  1.,  1.,  2.])