The windrose method provides one windrose/wind count
plot type. Based on the count matrix (windrose_get_counts)
this function returns a matrix with hex colors (with alpha channel)
and a data.frame used for the legend.
windrose_get_cols(x, col, p = 1, ncol = 50L)2-D matrix with counts (see windrose_get_counts).
single hex color, or a vector of hex colors. Alpha channel will be removed.
numeric value, power parameter for non-linear color transformation.
integer, if col is a single value the color will be repeated
ncol times. Default is 50L.
Returns a list with two elements: colormatrix of the same
dimension as x with colors for the different bins based on the
counts, and legend with levels and colors for the color legend of the
plot.