# mstdTopN

Syntax

mstdTopN(X, S, window, top, [ascending=true], [tiesMethod=’oldest’])

Please see Moving TopN Functions (mTopN functions) for the parameters and windowing logic.

Details

After stably sorting S in the specified ascending order, the function calculates the unbiased sample standard deviation of the first top elements of X in the sliding window.

Examples

```\$ X = 1..7
\$ S = 0.3 0.5 0.1 0.1 0.5 0.2 0.4
\$ mstdTopN(X, S, 4, 2)
[,0.707106781186548,1.414213562373095,0.707106781186548,0.707106781186548,0.707106781186548,1.414213562373095]

\$ X = NULL 1 2 3 4 NULL 5
\$ S = 3 5 1 1 5 2 4
\$ mstdTopN(X, S, 4, 2)
[,,,0.707106781186548,0.707106781186548,0.707106781186548,]

\$ X = matrix(1..5, 6..10)
\$ S = 2022.01.01 2022.02.03 2022.01.23 2022.04.06 2021.12.29
\$ mstdTopN(X, S, 3, 2)
```

#0

#1

0.707106781186548

0.707106781186548

1.414213562373095

1.414213562373095

0.707106781186548

0.707106781186548

1.414213562373095

1.414213562373095

```\$ X = matrix(1..5, 6..10)
\$ S = matrix(2022.01.01 2022.02.03 2022.01.23 NULL 2021.12.29,NULL 2022.02.03 2022.01.23 2022.04.06 NULL)
\$ mstdTopN(X, S, 3, 2)
```

#0

#1

0.7071

1.4142

0.7071

0.7071

0.7071

1.4142

0.7071

Related function: mstd