MALDIquant (version 1.4)

calibrate-methods: Calibrates intensity matrix.

Description

This function calibrates intensities of an intensity matrix created by intensityMatrix.

Usage

calibrate(x, ...)

Arguments

x

matrix, an intensity matrix created by intensityMatrix. (Rows have to contain samples and columns features (peaks).)

...

arguments to be passed to other functions (unneeded until now).

Value

• Returns a calibrated matrix (scale/calibration factors as attribute).

Details

First a median spectrum/feature list is calculated to be used as reference. Afterwards each sample is divided by the median of the ratios of sample intensities to reference intensities.

See Also

AbstractMassObject,

Examples

## load library
library("MALDIquant");

## create example matrix
m <- matrix(c(1, 2, 3, 
              3, 6, 9), 
            nrow=2, byrow=TRUE, dimnames=list(paste("samples", 1:2, sep=""),
                                              paste("peaks", LETTERS[1:3])));

## show matrix
m

## show calibrated matrix
calibrate(m);