R: Shift starting points in genetic maps

shiftmap {qtl} | R Documentation

## Shift starting points in genetic maps

### Description

Shift starting points in a genetic map to a set of defined positions

### Usage

    shiftmap(object, offset=0)

### Arguments

`object` | An object of class `cross` (see `read.cross` for details) or `map` (see `sim.map` for details).
`offset` | Defines the starting position for each chromosome. This should be a single value (to be used for all chromosomes) or a vector with length equal to the number of chromosomes, defining individual starting positions for each chromosome. For a sex-specific map (as in a 4-way cross), we use the same offset for both the male and female maps.

### Value

If the input is a `map` object, a `map` object is returned; if the input is a `cross` object, a `cross` object is returned. In either case, the positions of markers are shifted so that the starting positions are as in `offset`.

### Author(s)

Karl W Broman, kbroman@biostat.wisc.edu

### See Also

`replace.map`, `est.map`

### Examples

    data(hyper)
    shiftedhyper <- shiftmap(hyper, offset=0)
    par(mfrow=c(1,2))
    plotMap(hyper, shift=FALSE, alternate.chrid=TRUE)
    plotMap(shiftedhyper, shift=FALSE, alternate.chrid=TRUE)

[Package qtl version 1.41-6 Index]