zt {fishmethods}

Z-transform or center a time series

Description

Z-transforms observations of a time series or centers observations of a time series to the mean.

Usage

zt(x = NULL, ctype = 1)

Arguments

x

vector of observations. Missing values are allowed.

ctype

the type of transformation. 1 = Z transform ((x - mean x)/ sd x); 2 = center (x - mean x). Default = 1

Details

Z-transforms observations of a time series or centers observations of a time series to the mean.

Value

vector containing the transformed time series.

Author(s)

Gary A. Nelson, Massachusetts Division of Marine Fisheries [e-mail]

Examples

data(wolffish)
zt(wolffish$index)