tmfirst

Syntax

tmfirst(T, X, window)

Please see Time-Based Moving Functions (tm-functions) for the parameters and windowing logic.

Details

Return the first element of X in a sliding window.

Examples

$ T = 1 1 1 2 5 6
$ X = 1 4 NULL -1 NULL 4
$ m = table(T as t,X as x)
$ select *, tmfirst(t, x, 3) from m

t

x

tmfirst_t

1

1

1

1

4

1

1

1

2

-1

1

5

6

4

$ T = 2021.01.02 2021.01.02  2021.01.04  2021.01.05 2021.01.07 2021.01.08
$ X = 3 4 NULL -1 2 4
$ m = table(T as t,X as x)
$ select *, tmfirst(t, x, 3d) from m

t

x

tmfirst_t

2021.01.02

3

2021.01.02

4

3

2021.01.04

3

2021.01.05

-1

2021.01.07

2

-1

2021.01.08

4

2

$ select *, tmfirst(t, x, 1w) from m

t

x

tmfirst_t

2021.01.02

3

2021.01.02

4

3

2021.01.04

3

2021.01.05

-1

3

2021.01.07

2

3

2021.01.08

4

3

Related functions: first