rxCube: Cross Tabulation
rxCube to create efficiently represented contingency tables from
cross-classifying factors using a formula interface. It performs equivalent
calculations to the
rxCrossTabs function, but returns its results in a
rxCube(formula, data, outFile = NULL, pweights = NULL, fweights = NULL, means = TRUE, cube = TRUE, rowSelection = NULL, transforms = NULL, transformObjects = NULL, transformFunc = NULL, transformVars = NULL, transformPackages = NULL, transformEnvir = NULL, overwrite = FALSE, useSparseCube = rxGetOption("useSparseCube"), removeZeroCounts = useSparseCube, returnDataFrame = FALSE, blocksPerRead = rxGetOption("blocksPerRead"), rowsPerBlock = 100000, reportProgress = rxGetOption("reportProgress"), verbose = 0, computeContext = rxGetOption("computeContext"), ...) ## S3 method for class `rxCube': print (x, header = TRUE, ...) ## S3 method for class `rxCube': summary (object, header = TRUE, ...) ## S3 method for class `rxCube': as.data.frame (x, row.names = NULL, optional = FALSE, ...) ## S3 method for class `rxCube': subset (x, ...) ## S3 method for class `rxCube': [ (x, ...)
formula as described in rxFormula with the cross-classifying variables (separated by
:) on the right hand side. Independent variables must be factors. If present, the dependent variable must be numeric.
either a data source object, a character string specifying a .xdf file, or a data frame object containing the cross-classifying variables.
NULL, a character string specifying a .xdf file, or an RxXdfData object. If not NULL, the cube results will be written out to an .xdf file and an
RxXdfData object will be returned.
outFile is not supported when using distributed compute contexts.
character string specifying the variable to use as probability weights for the observations.
character string specifying the variable to use as frequency weights for the observations.
logical flag. If
TRUE (default), the mean values of the dependent variable are returned. Otherwise, the variable summations are returned.
logical flag. If
TRUE, the C++ cube functionality is called.
name of a logical variable in the data set (in quotes) or a logical expression using variables in the data set to specify row selection. For example,
rowSelection = "old" will use only observations in which the value of the variable
rowSelection = (age > 20) & (age < 65) & (log(income) > 10) will use only observations in which the value of the
age variable is between 20 and 65 and the value of the
log of the
income variable is greater than 10. The row selection is performed after processing any data transformations (see the arguments
transformFunc). As with all expressions,
rowSelection can be defined outside of the function call using the expression function.
an expression of the form
list(name = expression, ...) representing the first round of variable transformations. As with all expressions,
rowSelection) can be defined outside of the function call using the expression function.
a named list containing objects that can be referenced by
variable transformation function. The variables used in the transformation function must be specified in
transformVars if they are not variables used in the model. See rxTransform for details.
character vector of input data set variables needed for the transformation function. See rxTransform for details.
character vector defining additional R packages (outside of those specified in
rxGetOption("transformPackages")) to be made available and preloaded for use in variable transformation functions, e.g., those explicitly defined in RevoScaleR functions via their
transformFunc arguments or those defined implicitly via their
rowSelection arguments. The
transformPackages argument may also be
NULL, indicating that no packages outside
rxGetOption("transformPackages") will be preloaded.
user-defined environment to serve as a parent to all environments developed internally and used for variable data transformation. If
transformEnvir = NULL, a new "hash" environment with parent
baseenv() is used instead.
logical value. If
TRUE, an existing
outFile will be overwritten.
overwrite is ignored
logical value. If
TRUE, sparse cube is used.
logical flag. If
TRUE, rows with no observations will be removed from the output. By default, it has the same value as
useSparseCube. For large cube computation, this should be set to
TRUE, otherwise R may run out of memory even if the internal C++ computation succeeds.
logical flag. If
TRUE, a data frame is returned, otherwise a list is returned. Ignored if
outFile is specified and is not
NULL. See the Details section for more information.
number of blocks to read for each chunk of data read from the data source.
maximum number of rows to write to each block in the
outFile (if it is not
integer value with options:
0: no progress is reported.
1: the number of processed rows is printed and updated.
2: rows processed and timings are reported.
3: rows processed and all timings are reported.
integer value. If
0, no additional output is printed. If
1, additional summary information is printed.
a valid RxComputeContext. The
RxHadoopMR compute contexts distribute the computation among the nodes specified by the compute context; for other compute contexts, the computation is distributed if possible on the local computer.
additional arguments to be passed directly to the Revolution Compute Engine.
output objects from rxCube function.
logical value. If
TRUE, header information is printed.
row.names argument passed unaltered to the underlying
optional argument passed unaltered to the underlying
The output of the
rxCube function is essentially the same as that
produced by rxCrossTabs except that it is presented in a
different format. While the
rxCrossTabs function produces lists of
contingency tables (where each table is a matrix), the
outputs a single list (or data frame, or .xdf file) containing one column for each variable
specified in the formula, plus a
"Counts" column. The columns
corresponding to independent variables contain the factor levels of
that variable, replicated as necessary. If a dependent variable is specified
in the formula, an output column of the same name is produced and contains the
mean values of the categories defined by the interaction of the
"Counts" column contains the counts of the interactions used to
form the corresponding means.
outFileis not NULL: an
RxXdfDataobject representing the output .xdf file. In this case, the value for
returnDataFrame = FALSE: an object of class rxCube that is also of class
"list". This is the default.
returnDataFrame = TRUE: an object of class
In all cases, the names of the output columns are those of the
variables defined in the formula plus a
See the Details section for more information regarding the content of these
Microsoft Technical Support
# Basic data.frame source example admissions <- as.data.frame(UCBAdmissions) admissCube <- rxCube(Freq ~ Gender : Admit, data = admissions) admissCube # XDF example: small subset of census data censusWorkers <- file.path(rxGetOption("sampleDataDir"), "CensusWorkers.xdf") censusCube <- rxCube(wkswork1 ~ sex : F(age), data = censusWorkers, pweights = "perwt", blocksPerRead = 3, returnDataFrame = TRUE) censusCube censusCube$age <- as.integer(as.character(censusCube$F_age)) rxLinePlot(wkswork1 ~ age, groups=sex, data = censusCube) # perform a census cube, limiting the analysis to ages # on the interval [20, 65]. Verify the age range from the output. censusCubeAge.20.65 <- rxCube(wkswork1 ~ sex : F(age), data = censusWorkers, rowSelection = age >= 20 & age <= 65) ageRange <- range(as.numeric(as.character(censusCubeAge.20.65$F_age))) (ageRange >= 20 & ageRange <=65) # Create a local data.frame and define a transformation # function to be applied to the data prior to processing. myDF <- data.frame(sex = c("Male", "Male", "Female", "Male"), age = factor(c(20,20,12,15)), score = 1.1:4.1, sport=c(1:3,2)) # Use the 'transforms' argument to dynamically transform the # variables of the data source. Here, we form a named list of # transformation expressions. To avoid evaluation when assigning # to a local variable, we wrap the transformation list with expression(). transforms <- expression(list( scoreDoubled = score * 2, sport = factor(sport, labels=c("tennis", "golf", "football")))) rxCube(scoreDoubled ~ sport : sex, data = myDF, transforms = transforms, removeZeroCounts=TRUE) # Arithmetic formula expression only (no transformFunc specification). rxCube(log(score) ~ age : sex, data = myDF) # No transformFunc or arithmetic expressions in formula. rxCube(score ~ age : sex, data = myDF) # Transform a categorical variable to a continuous one and use it # as a response variable in the formula for cross-tabulation. # The transformation is equvalent to doing the following, which # is reflected in the cross-tabulation results. # # > as.numeric(as.factor(c(20,20,12,15))) - 1 #  2 2 0 1 myDF <- data.frame(sex = c("Male", "Male", "Female", "Male"), age = factor(c(20, 20, 12, 15)), score = 1.1:4.1) rxCube(N(age) ~ sex : F(score), data = myDF) # this should break because 'age' is a categorical variable ## Not run: try(rxCube(age ~ sex : score, data = myDF)) ## End(Not run) # frequency weighting fwts <- 1:4 sex <- c("Male", "Male", "Female", "Male") age <- c(20, 20, 12, 15) score <- 1.1:4.1 myDF1 <- data.frame(sex = sex, age = age, score = factor(score), fwts = fwts) myDF2 <- data.frame(sex = rep(sex, fwts), age = rep(age, fwts), score = factor(rep(score, fwts))) myCube1 <- rxCube(age ~ sex : score, data = myDF1, fweights = "fwts") myCube2 <- rxCube(age ~ sex : score, data = myDF2) all.equal(myCube1, myCube2, check.attributes = FALSE)