is.fullrank {limma} | R Documentation

## Check for Full Column Rank

### Description

Test whether a numeric matrix has full column rank.

### Usage

    is.fullrank(x)
    nonEstimable(x)

### Arguments

`x` | a numeric matrix or vector

### Details

`is.fullrank` is used to check the integrity of design matrices in limma, for example after subsetting operations.

`nonEstimable` is used by `lmFit` to report which coefficients in a linear model cannot be estimated.

### Value

`is.fullrank` returns `TRUE` or `FALSE`.
`nonEstimable` returns a character vector of names for the columns of `x` which are linearly dependent on previous columns. If `x` has full column rank, then the value is `NULL`.

### Author(s)

Gordon Smyth

### Examples

    # TRUE
    is.fullrank(1)
    is.fullrank(cbind(1,0:1))

    # FALSE
    is.fullrank(0)
    is.fullrank(matrix(1,2,2))
    nonEstimable(matrix(1,2,2))

[Package limma version 2.18.3 Index]