arrowDir: Arrow direction fitting for Arrowhead function from "shape"...

In rWind: Download, Edit and Include Wind and Sea Currents Data in Ecological and Evolutionary Analysis

Arrow direction fitting for Arrowhead function from "shape" package

Description

arrowDir adapts wind direction value to be used by Arrowhead function from "shape" package to plot wind direction for each coordinate.

Usage

arrowDir(W)

Arguments

W	An object of class rWind or a data.frame which should content a column named "dir".

Details

Angle argument of Arrowhead function from "shape" package needs to be fed in an anti-clockwise way, relative to x-axis, in degrees 0,360. arrowDir function adapts wind direction provided by wind.fit (clockwise, relative to y-axis ) to requirements of Arrowhead.

Value

A numeric vector with one angle per grid cell, in degrees anticlockwise from the positive x-axis, for plotting with shape::Arrowhead(). For an rWind_series, only the first time step is used.

Note

arrowDir function works always together with Arrowhead function from "shape" package.

Author(s)

Javier Fernández-López

References

Karline Soetaert (2017). shape: Functions for Plotting Graphical Shapes, Colors. R package version 1.4.3. https://CRAN.R-project.org/package=shape

See Also

wind.dl

Examples

data(wind.data)

# Create a vector with wind direction (angles) adapted
alpha <- arrowDir(wind.data)
# Plot arrows if the optional shape package is available
if (requireNamespace("shape", quietly = TRUE)) {
plot(wind.data$lon, wind.data$lat, type = "n")
shape::Arrowhead(wind.data$lon, wind.data$lat,
  angle = alpha,
  arr.length = 0.1, arr.type = "curved"
)
}

rWind documentation built on Oct. 18, 2026, 5:08 p.m.