R: Interpolation of MS measurement resolution

getR {enviPat} | R Documentation

## Interpolation of MS measurement resolution

### Description

Given a set of MS measurement resolutions (R) as a function of measurement mass (m/z), getR interpolates R for any given molecular mass(es) calculated by `check_chemform` using `smooth.spline`.

### Usage

    getR(checked, resmass, nknots = 13, spar = 0.1, plotit = TRUE)

### Arguments

`checked` | Dataframe produced by `check_chemform`.
`resmass` | Dataframe with two columns, resolution and mass; such as the list entries in `resolution_list`.
`nknots` | Integer number of knots to use for the smoothing spline. Default = 6. See also `smooth.spline`.
`spar` | Smoothing parameter, (0,1]. See also `smooth.spline`.
`plotit` | Plot results, `TRUE/FALSE` ?

### Value

Vector with resolutions.

### Note

`check_chemform` gives molecular masses (m/z) for z=+/-1 only. If z>1 or z<-1 is required, molecular mass entries in argument checked have to be divided accordingly to be consistent.

### Author(s)

Martin Loos, Christian Gerber

### See Also

`smooth.spline` `check_chemform` `resolution_list`

### Examples

    data(resolution_list)
    resmass<-resolution_list[[4]]
    data(isotopes)
    data(chemforms)
    checked<-check_chemform(isotopes,chemforms)
    resolution<-getR(checked,resmass,nknots=13,spar=0.1,plotit=TRUE)

    # same for z=-2:
    checked<-check_chemform(isotopes,chemforms)
    checked[,3]<-(checked[,3]/abs(-2))
    resolution<-getR(checked,resmass,nknots=13,spar=0.1,plotit=TRUE)

[Package enviPat version 2.4 Index]