matrix2longdf: Transform a matrix into a long-format data.frame
In ribiosUtils: Utilities from and Interface to the Bioinfo-C (BIOS) Library

Description Usage Arguments Details Value Note Author(s) Examples

The function converts a matrix into a long-format, three-column data.frame, containing row, columna nd value. Such ‘long’ data.frames can be useful in data visualization and modelling.

matrix2longdf(
  mat,
  row.names,
  col.names,
  longdf.colnames = c("row", "column", "value")
)

`mat`	A matrix
`row.names`	Character, row names to appear in the `data.frame`. If missing, the `rownames` of the matrix will be used. If set to `NULL`, or if the matrix `rownames` are `NULL`, a integer index vector starting from 1 will be used.
`col.names`	Charater, column names to appear in the `data.frame`. The rule of handling missing or NULL parameters is the same as `row.names` described above.
`longdf.colnames`	Character, column names of the output long data frame

The function converts a matrix into a three-column, ‘long’ format data.frame containing row names, column names, and values of the matrix.

A data.frame object with three columns: row, column and value. If the input matrix is of dimesion MxN, the returning data.frame is of the dimension MNx3.

The length of row.names and col.names should be as the same as the matrix dimension. Otherwise the function raises warnings.

Jitao David Zhang <jitao_david.zhang@roche.com>

test.mat <- matrix(1:12, ncol=4, nrow=3, dimnames=list(LETTERS[1:3],
LETTERS[1:4]))
print(test.mat)
print(matrix2longdf(test.mat))
print(matrix2longdf(test.mat, longdf.colnames=c("From", "To", "Time")))