# NxConv - Time Series Convolution Operator

Returns an array of cells for the convolution operator of two time series.

## Syntax

NxConv(X, Y)

X is the univariate time series data (one dimensional array of cells (e.g. rows or columns)).

Y is the second time series function (e.g. filter) values (one dimensional array of cells (e.g. rows or columns)).

## Remarks

1. The time series must be homogeneous or equally spaced.
2. The two time series can have different sizes.
3. Presample values of $X_t$ and $Y_t$ are assumed to be zero.
4. The convolution operator is described as follows:

$$Z_t=\sum_{j=\mathrm{max}\left ( 1,t-M+1 \right )}^{\mathrm{min}\left ( N,t+M-1 \right )}X_jY_{M-t+j}$$

Where:
• $Z_t$ is the convolution time series.
• $X_t$ is the first time series, with $N$ observations.
• $Y_t$ is the second time series, with $M$ observations.
• $t\in \left[ 1,N+M \right]$, i.e., $1\leq t \leq N+M$.
5. The function was added in version 1.62 DEWDROP.