Returns an array of cells for the differenced time series (i.e. (1L^S)^D).
Syntax
DIFF(X, Order, K, D)
X is the univariate time series data (a one dimensional array of cells (e.g. rows or columns)).
Order is the time order in the data series (i.e. the first data point's corresponding date (earliest date=1 (default), latest date=0)).
Order  Description 

1  ascending (the first data point corresponds to the earliest date) (default) 
0  descending (the first data point corresponds to the latest date) 
K is the seasonal difference order (e.g. K=0 (no lag), S=1 (1st lag), etc.) If missing, the default value of one is assumed.
D is the number of repeated differencing (e.g. d=0 (none), d=1 (difference once), 2= (difference twice), etc.). If missing, the default value of one is assumed.
Remarks
 The DIFF operator is defined as follow :
$$Y_t=\left(1L^k\right)^d X_t$$
Where:
 $\left[y_t\right]$ is the difference time series.
 $\left[x_t\right]$ is the input time series.
 $L$ is the lag operator.
 $k$ is the seasonality length.
 $d$ is the difference order.
 The size of the output differenced time series is equal to the input time series, but with the first $s \times d$ observations are set to missing (i.e. #N/A).
 The seasonal difference order (i.e. k) must be nonnegative and smaller than the time series size (i.e. T).
$0 \leq k \leq T1 $  The input time series is homogenous and equally spaced.
 The time series may include missing values (e.g. #N/A) at either end.
Examples
Example 1:


Files Examples
References
 D. S.G. Pollock; Handbook of Time Series Analysis, Signal Processing, and Dynamics; Academic Press; Har/Cdr edition(Nov 17, 1999), ISBN: 125609906
 James Douglas Hamilton; Time Series Analysis; Princeton University Press; 1st edition(Jan 11, 1994), ISBN: 691042896
 Tsay, Ruey S.; Analysis of Financial Time Series; John Wiley & SONS; 2nd edition(Aug 30, 2005), ISBN: 0471690740
 Box, Jenkins and Reisel; Time Series Analysis: Forecasting and Control; John Wiley & SONS.; 4th edition(Jun 30, 2008), ISBN: 470272848
 Walter Enders; Applied Econometric Time Series; Wiley; 4th edition(Nov 03, 2014), ISBN: 1118808568
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