# isPeak

Syntax

isPeak(X, [strict=true])

Arguments

X is a numeric vector/matrix/table.

strict is a Boolean value. The default value is true.

• If strict = true, the adjacent elements cannot be NULL and are strictly smaller than the element;

• If strict = false, the adjacent elements cannot be NULL and are no greater than the element.

Details

If X is a vector, check if each element in X is the peak.

If X is a matrix, perform the aforementioned calculations on each column and return a matrix of the same size as X.

If X is a table, only the numeric columns are involved in the calculations.

Examples

```\$ v = [1, 2.2, 2.2, 2.2, 2.3, 1, 1.2]
\$ isPeak(v)
[0,0,0,0,1,0,0]

\$ v = [1, 2.2, 2.2, 2.2, 1.6, 1, 1.2]
\$ isPeak(v)
[0,0,0,0,0,0,0]
\$ isPeak(v, false)
[0,1,1,1,0,0,0]

// Perform the calculations on each column in a matrix
\$ m = matrix(3.3 2.8 5.6 NULL 2.5 1.2, 4.5 3.5 4.6 2.8 3.9 NULL)
\$ isPeak(m)
```

#0

#1

0

0

0

0

0

1

0

0

0

0

0

0

```// Perform the calculations on the numeric columns in a table
\$ t = table(`01`01`00`01`02`00 as id, 2022.01.01 + 1..6 as date, 388.3 390.6 390.8 390.6 390.3 391.5 as price)
\$ isPeak(t)
```

id

date

price

01

2022.01.02

0

01

2022.01.03

0

00

2022.01.04

1

01

2022.01.05

0

02

2022.01.06

0

00

2022.01.07

0

Related function: isValley