Special functions

$fill$_$missing()$

Syntax	Example

To better understand this function, let's suppose you have a set of variables that you want to sum up together.

$fill$_$missing(A + B + C + D)$

The variables A, B, C, and D don't have data in all of the timestamps, as shown in the table below, so the fill missing() function is used to fill in the gaps and do the calculation. The following examples are based on the table:

Date	A	B	C	D	Output

By default, the fill_missing() expression makes the first_fill parameter as "ffill", meaning that the function will fill the gaps forward, starting at a point where it has enough data to fill the gaps for all the involved time series. The result would be as follows:

Date	A	B	C	D	Output

$fill$_$missing(A + B + C + D, first$_$fill="bfill")$

On the other hand, It's also possible to make the first_fill a "bfill" The gaps would be filled in the following manner:

Date	A	B	C	D	Output

$fill$_$missing(A + B + C + D, fill$_$value=0)$

Date	A	B	C	D	Output

$cumsum()$

Syntax	Example	Output

$where()$

Syntax	Example	Output

$diff()$

Syntax	Example	Output

$shift()$

Sintax	Example	Output