vec.y: Calculate vertical component vectors

In bjornbrooks/PolarMetrics: Functions for analyzing seasonal patterns in environmental variables

Description

Calculate the vertical vector component for each pair of polar coordinates.

Usage

vec.y(r, v)

Arguments

r	A vector of numeric values representing dates in radians.
v	A vector of numeric values representing a uniformly sampled series of data that vary over multiple cycles.

Details

vec.y calculates the length of the vertical vector component of each polar coordinate pair. Given an angle r in radians and a corresponding amplitude v the vertical vector component, Vy, is calculated by:

VY(r, v) = v * sin(r)

.

Value

Returns the length of the vertical vector component for each polar coordinate pair.

Author(s)

Bjorn J. Brooks, Danny C. Lee, William W. Hargrove, Lars Y. Pomara

References

Brooks, B.J., Lee, D.C., Desai, A.R., Pomara, L.Y., Hargrove, W.W. (2017). Quantifying seasonal patterns in disparate environmental variables using the PolarMetrics R package.

Examples

dpy <- 365                 # Days/yr
data(mndvi)                # Load data
t <- as.vector(mndvi$day)  # Days since January 1, 2000
r <- t2rad(t,dpy)          # Transform days of year to radians
v <- as.vector(mndvi$wc)   # MODIS NDVI for Willow Creek tower, WI
vy <- vec.y(r,v)           # The vertical vector components

bjornbrooks/PolarMetrics documentation built on Dec. 22, 2020, 1:42 a.m.