cf.Data.diff¶

Data.
diff
(axis=1, n=1, inplace=False)[source]¶ Calculate the nth discrete difference along the given axis.
The first difference is given by
x[i+1]  x[i]
along the given axis, higher differences are calculated by usingdiff
recursively.The shape of the output is the same as the input except along the given axis, where the dimension is smaller by n. The data type of the output is the same as the type of the difference between any two elements of the input.
New in version 3.2.0.
 Parameters
 axis: int, optional
The axis along which the difference is taken. By default the last axis is used. The axis argument is an integer that selects the axis corresponding to the given position in the list of axes of the data array.
 n: int, optional
The number of times values are differenced. If zero, the input is returned asis. By default n is
1
. inplace:
bool
, optional If True then do the operation inplace and return
None
.
 Returns
Examples
>>> d = cf.Data(numpy.arange(12.).reshape(3, 4)) >>> d[1, 1] = 4.5 >>> d[2, 2] = 10.5 >>> print(d.array) [[ 0. 1. 2. 3. ] [ 4. 4.5 6. 7. ] [ 8. 9. 10.5 11. ]] >>> print(d.diff().array) [[1. 1. 1. ] [0.5 1.5 1. ] [1. 1.5 0.5]] >>> print(d.diff(n=2).array) [[ 0. 0. ] [ 1. 0.5] [ 0.5 1. ]] >>> print(d.diff(axis=0).array) [[4. 3.5 4. 4. ] [4. 4.5 4.5 4. ]] >>> print(d.diff(axis=0, n=2).array) [[0. 1. 0.5 0. ]] >>> d[1, 2] = cf.masked >>> print(d.array) [[0.0 1.0 2.0 3.0] [4.0 4.5  7.0] [8.0 9.0 10.5 11.0]] >>> print(d.diff().array) [[1.0 1.0 1.0] [0.5  ] [1.0 1.5 0.5]] >>> print(d.diff(n=2).array) [[0.0 0.0] [  ] [0.5 1.0]] >>> print(d.diff(axis=0).array) [[4.0 3.5  4.0] [4.0 4.5  4.0]] >>> print(d.diff(axis=0, n=2).array) [[0.0 1.0  0.0]]