snapKrig (version 0.0.2)

sk_add_bins: Add bin labels to a variogram data frame

Description

Helper function for grouping the rows of input data frame vg into n_bins bins according to the value of the (numeric) distance column d. This uses either base::cut or, if probs is supplied, stats::quantile.

Usage

sk_add_bins(vg, n_bin = 25, probs = NULL)

Value

same as input vg but with integer column bin added/modified

Arguments

vg

data frame with numeric column 'd'

n_bin

integer number of distance bins to assign

probs

numeric vector of quantile probabilities to establish breakpoints (length n_bin+1)

Details

By default, the function sets probs to a sequence of length 1+n_bin evenly splitting the interval [0,1] to ensure approximately equal sample sizes for each bin. Setting probs=NA instead sets the bin endpoints such that the range of distances is split evenly (note this may produce empty bins)

The function is called by sk_sample_vg and sk_plot_semi (when column bin is missing). It can also be used to recompute bins after an rbind of multiple variogram data frames.

See Also

Other variogram functions: sk_vario_fun()

Examples

distance_df = data.frame(d=runif(25))
sk_add_bins(distance_df)

# specify fewer bins and set up quantiles explicitly
sk_add_bins(distance_df, n_bin = 5) # same as ...
sk_add_bins(distance_df, n_bin = 5, probs=seq(0, 1, length.out=6))

# break range of distances into evenly spaced bins (of varying sample sizes)
sk_add_bins(distance_df, n_bin = 5, probs=NULL)