xt: Construct a two-way frequency table (matrix) from a 2 or 3...
In bjornbrooks/landat: R functions for calculating IT statistics

Description Usage Arguments Details Value Author(s) References Examples

Construct a two-way frequency table (matrix) by reforming and aggregating counts into bins.

1	xt(trn, fr.col, to.col, cnt.col = NULL, brk = NULL)

trn

An array or data frame with two or three columns (either from, to or from, to, count). Each row should at least designate the from-group & to-group (count is optional).

From	To	Count
x1	x1	40
x1	x2	89
...	...	...

fr.col

The column number of t for the ‘from’ variable, which will be reformed to vary across columns in the output matrix.

to.col

The column number of t for the ‘to’ variable, which will be reformed to vary across rows in the output matrix.

cnt.col

(optional) The column number of t for the ‘count’ variable. If unspecified then each row will be counted as one observation.

brk

(optional) Either a value indicating the number of bins to aggregate t into, or a vector specifying the breakpoints to use if probabilistically equivalent bin ranges are desired. Equivalent ranges can be calculated using brkpts.

xt requires an array or data frame of numeric values and returns a two-way table of frequencies that can be optionally grouped into bins of a specified range.

Returns a two-way table of frequencies in the form:

		Fr
	40	38	37	...
To	89	89	87	...
	75	74	89	...
	...	...	...	...

Bjorn J. Brooks, Lars Y. Pomara, Danny C. Lee

PAPER TITLE.

data(transitions)                # Load example data
b <- brkpts(transitions$phenofr, # 10 probabilistically
            10)                  #  equivalent breakpoints
m <- xt(transitions, fr.col=2,   # Construct a two-way table
        to.col=3, cnt.col=4,
        brk=b)