calc_t

A non-negative integer specifying the number of days to simulate.

A character string that specifies the desired trend function.
Options are:<ul>
<li>"no trend": No trend, either seasonal or long-term (default).</li>
<li>"cos1": A seasonal trend only.</li>
<li>"cos2": A seasonal trend with variable amplitude across years.</li>
<li>"cos3": A seasonal trend with steadily decreasing amplitude over time.</li>
<li>"linear": A linear long-term trend with no seasonal trend.</li>
<li>"curvilinear": A curved long-term trend with no seasonal trend.</li>
<li>"cos1linear": A seasonal trend plus a linear long-term trend.</li>
</ul>See the package vignette for examples of the shapes of these trends.

trend

A numeric value specifying the slope of the trend, to be used
with <code>trend = "linear"</code> or <code>trend = "cos1linear"</code>.

slope

A numeric value specifying the amplitude of the seasonal trend.
Must be between -1 and 1.

An R object specifying a customized function from
which to create a trend variable. Must accept the arguments <code>n</code>
and <code>mean</code>.

custom_func

Optional arguments to a custom trend function

Creates a trend vector for a continuous exposure.

Provides functions to create simulated time series of environmental
exposures (e.g., temperature, air pollution) and health outcomes for use in
power analysis and simulation studies in environmental epidemiology. This
package also provides functions to evaluate the results of simulation studies
based on these simulated time series. This work was supported by a grant
from the National Institute of Environmental Health Sciences (R00ES022631) and
a fellowship from the Colorado State University Programs for Research and
Scholarly Excellence.

calc_t: Create a continuous exposure trend vector

Description

Usage

Arguments

Value

Examples