RPPADesign-class {SuperCurve}R Documentation

The RPPADesign Class

Description

This class represents the information that describes how a particular set of RPPA slides was designed.

Usage

RPPADesign(raw, steps = NULL, series = NULL,
  grouping = c("byRow","byCol", "bySample", "blockSample"),
  ordering = c("decreasing","increasing"),
  alias = NULL, center = FALSE, controls = list())
seriesNames(design)
getSteps(design)
## S4 method for signature 'RPPADesign':
image(x, ...)
## S4 method for signature 'RPPADesign':
summary(object, ...)
## S4 method for signature 'RPPADesign':
names(x)

Arguments

raw A data frame or an RPPA object.
steps An optional numeric vector listing the dilution step associated with each spot, on a logarithmic scale.
series An optional character vector or factor identifying the dilution series to which each spot corresponds.
grouping Describes the way dilution series are oriented on the array.
ordering Are dilution series arranges in order of increasing or decreasing concentrations. Default is decreasing.
alias A data frame containing two columns: Alias and Sample
center A logical value: if TRUE, then dilution steps are centered around 0.
controls A list containing the character strings that identify control spots on the array.
x A RPPADesign object
object A RPPADesign object
design A RPPADesign object
... The usual extra arguments for generic or plotting routines.

Details

From their inception, reverse-phase protein array experiments have spotted samples on the array in dilution series. Thus, a critical aspect of the design and analysis is to understand how the dilution series are placed on the array.

The optional grouping and ordering arguments allow the user to specify several standard layouts without having to go into great detail. The most common layout is byRow, which indicates that each row of a subgrid on the array should be considered as a separate dilution series. Although considerably less common (for reasons related to the robotics of how arrays are printed), the byCol layout indicates that each column of a subgrid is its own dilution series. The bySample layout means that each unique sample name indicates its own dilution series. Finally, the blockSample layout indicates that all occurrences of a sample name within a subgrid (or block) refer to the same dilution series. The blockSample layout can be used, for example, when a dilution series is long enough to extend over more than one row of a subgrid. One layout we have seen used seven dilution steps followed by a control spot, contained in two successive rows of a design with 4x4 subgrids, leading to the pattern:

7 6 5 4

3 2 1 C

If the design of an RPPA experiment does not follow one of the built-in patterns, you can create an object by supplying vectors of dilution series names (in the series argument) and corresponding dilution steps (in the steps argument) that explicitly provide the mapping for each spot.

Value

The image method invisibly returns the displayed matrix of dilution steps.
The summary method returns the summary object of the layout data frame.
The names method returns a character vector.
The getSteps function returns a numeric vector containing, for each non-control spot, the step represented by that spot in its dilution series.
The seriesNames function returns a character vector containing the names of the unique (non-control) dilution series on the array.

Objects from the Class

Objects of the RPPADesign class should be constructed using the RPPADesign function.

Slots

layout:
A data frame
alias:
A data frame
sampleMap:
A character vector
controls:
A list containing the character strings that identify control spots on the array. Controls are not included as part of any dilution series.

Methods

image(x, ...)
The image method produces a two-dimensional graphical display of the layout design. Colors are used to represent different dilution steps, and laid out in the same pattern as the rows and columns of the array. This provides a visual check that the design has been specified correctly.
summary(object, ...)
The summary method lists the names of the control spots on the array and then prints a summary of the data frame describing the layout.
names(x)
The names method returns a character vector containing, for each non-control spot, the name of the dilution series to which that spot belongs.

Author(s)

Kevin R. Coombes <kcoombes@mdanderson.org>

References

KRC

See Also

RPPA

Examples

path <- system.file("rppaTumorData", package="SuperCurve")
erk2 <- RPPA("ERK2.txt", path=path)
design <- RPPADesign(erk2, grouping="blockSample", center=TRUE)
image(design)
summary(design)

design <- RPPADesign(erk2, grouping="blockSample",
                     controls=list("neg con", "pos con"))
image(design)
summary(design)

path <- system.file("rppaCellData", package="SuperCurve")
akt <- RPPA("Akt.txt", path=path)
# Uses duplicate 8-step dilution series within 4x4 subgrids.
# They are interleaved, with the top two identical rows
# containing the first 4 steps and the bottom two identical
# rows containing the last 4 steps.
steps <- rep(c(rep(8:5, 2), rep(4:1, 2)), 40) - 4.5
rep.temp <- factor(paste('Rep', rep(rep(1:2, each=4), 80), sep=''))
series <- factor(paste(as.character(akt@data$Sample),
                             as.character(rep.temp),
                             sep='.'))
design40 <- RPPADesign(akt, steps=steps, series=series)
image(design40)
summary(design40)


[Package SuperCurve version 0.931 Index]