missingProjector {compositions} | R Documentation

## Returns a projector the the observed space in case of missings.

### Description

Returns projectors on the observed subspace in the presence of missings.

### Usage

    missingProjector(x,...,by="s")
    ## S3 method for class 'acomp':
    missingProjector(x,has=is.NMV(x),...,by="s")
    ## S3 method for class 'aplus':
    missingProjector(x,has=is.NMV(x),...,by="s")
    ## S3 method for class 'rcomp':
    missingProjector(x,has=!(is.MAR(x)|is.MNAR(x)),...,by="s")
    ## S3 method for class 'rplus':
    missingProjector(x,has=!(is.MAR(x)|is.MNAR(x)),...,by="s")

### Arguments

`x` | a dataset or object of the given class
`has` | a boolean matrix of the same size indicating nonmissing values
`...` | additional arguments for generic purpose only
`by` | the name of the dataset dimension on `has` for tensorial computation with tensorA package

### Details

### Value

A dataset of N square matrices of dimension DxD (with N and D respectively equal to the number of rows and columns in `x`). Each of these matrices gives the projection of a data row onto its observed sub-space.
The function `sumMissingProjector` takes all these matrices and sums them, generating a "summary" of observed sub-spaces. This matrix is useful to obtain estimates of the mean (and variance, in the future) still unbiased in the presence of lost values (only of type MAR, stricly-speaking, but anyway useful for any type of missing value, when used with care).

### Author(s)

K.G.van den Boogaart

### References

Boogaart, K.G. v.d. (2006) Concepts for handling of zeros and missing values in compositional data, in E. Pirard (ed.) (2006)Proccedings of the IAMG'2006 Annual Conference on "Quantitative Geology from multiple sources", September 2006, Liege, Belgium, S07-01, 4pages, http://www.math-inf.uni-greifswald.de/~boogaart/Publications/iamg06_s07_01.pdf

### See Also

### Examples

    data(SimulatedAmounts)
    x <- acomp(sa.lognormals)
    xnew <- simulateMissings(x,detectionlimit=0.05,MAR=0.05,MNAR=0.05,SZ=0.05)
    xnew
    plot(missingSummary(xnew))

    missingProjector(acomp(xnew))
    missingProjector(rcomp(xnew))
    missingProjector(aplus(xnew))
    missingProjector(rplus(xnew))

[Package compositions version 0.91-6 Index]