calc_t: Create a continuous exposure trend vector

In eesim: Simulate and Evaluate Time Series for Environmental Epidemiology

Description

Creates a trend vector for a continuous exposure.

Usage

calc_t(n, trend = "no trend", slope = 1, amp = 0.6, custom_func = NULL,
  ...)

Arguments

n	A non-negative integer specifying the number of days to simulate.
trend	A character string that specifies the desired trend function. Options are: "no trend": No trend, either seasonal or long-term (default). "cos1": A seasonal trend only. "cos2": A seasonal trend with variable amplitude across years. "cos3": A seasonal trend with steadily decreasing amplitude over time. "linear": A linear long-term trend with no seasonal trend. "curvilinear": A curved long-term trend with no seasonal trend. "cos1linear": A seasonal trend plus a linear long-term trend. See the package vignette for examples of the shapes of these trends.
slope	A numeric value specifying the slope of the trend, to be used with trend = "linear" or trend = "cos1linear".
amp	A numeric value specifying the amplitude of the seasonal trend. Must be between -1 and 1.
custom_func	An R object specifying a customized function from which to create a trend variable. Must accept the arguments n and mean.
...	Optional arguments to a custom trend function

Value

A numeric vector of simulated exposure values for each study day, to be used to generate data with seasonal trends.

Examples

calc_t(5, "cos3", amp = .5)

eesim documentation built on May 2, 2019, 7:30 a.m.