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aroma.affymetrix (version 2.2.0)

AffinePlm: The AffinePlm class

Description

Package: aroma.affymetrix Class AffinePlm Object ~~| ~~+--Model ~~~~~~~| ~~~~~~~+--UnitModel ~~~~~~~~~~~~| ~~~~~~~~~~~~+--MultiArrayUnitModel ~~~~~~~~~~~~~~~~~| ~~~~~~~~~~~~~~~~~+--ProbeLevelModel ~~~~~~~~~~~~~~~~~~~~~~| ~~~~~~~~~~~~~~~~~~~~~~+--AffinePlm Directly known subclasses: AffineCnPlm, AffineSnpPlm public static class AffinePlm extends ProbeLevelModel This class represents affine model in Bengtsson & H�ssjer{Hossjer} (2006).

Usage

AffinePlm(..., background=TRUE)

Arguments

...
Arguments passed to ProbeLevelModel.
background
If TRUE, background is estimate for each unit group, otherwise not. That is, if FALSE, a linear (proportional) model

encoding

latin1

Fields and Methods

Methods: rll{ getAsteriskTags - getProbeAffinityFile - } Methods inherited from ProbeLevelModel: calculateResidualSet, calculateWeights, fit, getAsteriskTags, getCalculateResidualsFunction, getChipEffectSet, getProbeAffinityFile, getResidualSet, getWeightsSet Methods inherited from MultiArrayUnitModel: getListOfPriors, setListOfPriors, validate Methods inherited from UnitModel: findUnitsTodo, getAsteriskTags, getFitSingleCellUnitFunction Methods inherited from Model: fit, getAlias, getAsteriskTags, getDataSet, getFullName, getName, getPath, getRootPath, getTags, setAlias, setTags Methods inherited from Object: asThis, getChecksum, $, $<-, [[, [[<-, as.character, attach, attachLocally, clearCache, clearLookupCache, clone, detach, equals, extend, finalize, gc, getEnvironment, getFieldModifier, getFieldModifiers, getFields, getInstantiationTime, getStaticInstance, hasField, hashCode, ll, load, objectSize, print, registerFinalizer, save

Model

For a single unit group, the affine model is: $$y_{ik} = a + \theta_i \phi_k + \varepsilon_{ik}$$ where $a$ is an offset common to all probe signals, $\theta_i$ are the chip effects for arrays $i=1,...,I$, and $\phi_k$ are the probe affinities for probes $k=1,...,K$. The $\varepsilon_{ik}$ are zero-mean noise with equal variance. The model is constrained such that $\prod_k \phi_k = 1$. Note that with the additional constraint $a=0$ (see arguments above), the above model is very similar to MbeiPlm. The differences in parameter estimates is due to difference is assumptions about the error structure, which in turn affects how the model is estimated.

References

Bengtsson & H�ssjer{Hossjer} (2006).