DescTools (version 0.99.30)

Freq2D: Bivariate (Two-Dimensional) Frequency Distribution

Description

Calculate a frequency distribution for two continuous variables.

Usage

Freq2D(x, …)
# S3 method for formula
Freq2D(formula, data, subset, …)
# S3 method for default
Freq2D(x, y, n=20, pad=0, dnn=NULL, …)

Arguments

x

a vector of x values, or a data frame whose first two columns contain the x and y values.

y

a vector of y values.

formula

a formula, such as y~x.

data

a data.frame, matrix, or list from which the variables in formula should be taken.

subset

an optional vector specifying a subset of observations to be used.

n

the desired number of bins for the output, a scalar or a vector of length 2.

pad

number of rows and columns to add to each margin, containing only zeros.

dnn

the names to be given to the dimensions in the result.

…

named arguments to be passed to the default method.

Value

The layout argument specifies one of the following formats for the binned frequency output:

1. matrix that is easy to read, aligned like a scatterplot.

2. list with three elements (x, y, matrix) that can be passed to various plotting functions.

3. data.frame with three columns (x, y, frequency) that can be analyzed further.

Details

The exact number of bins is determined by the pretty function, based on the value of n.

Padding the margins with zeros can be helpful for subsequent analysis, such as smoothing.

The print logical flag only has an effect when layout=1.

See Also

cut, table, and print.table are the basic underlying functions.

Examples

# NOT RUN {
Freq2D(quakes$long, quakes$lat, dnn="")
Freq2D(lat~long, quakes, n=c(10,20), pad=1)

# range(Freq2D(saithe, print=FALSE))

# Layout, plot
# Freq2D(saithe, layout=2)
# Freq2D(saithe, layout=3)
# contour(Freq2D(saithe, layout=2))
# lattice::contourplot(Freq~Bio+HR, Freq2D(saithe,layout=3))
# }