This is a wrapper for
latticeParseFormula that allows the option of using
a "." for the conditioning variables (i.e. after "|") instead of explicitly
writing them out. When so used, it means "all variables in the data argument
except those already used to the left of the |". See the Help for
strucplot for examples.
An optional data frame containing values for any variables in the formula. Default = list(), which means that all variables will be looked up in the formula's environment.
Note that this is a convenience option only; the conditioning can always be explicitly given. Also note that the two options cannot be combined: either a "." and only a "." must be used or all the conditioning variables must be written out.
latticeParseFormula with an additional "form"
attribute that is the formula used with all conditioning explicitly
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exdat <- data.frame(x = 1:5, alongname = sample( letters[1:3],5, rep=TRUE), butalongername = sample(LETTERS[1:2],5, rep = TRUE)) y <- runif(5) strucParseFormula (y ~ x| alongname*butalongername, data = exdat) # The same strucParseFormula (y ~ x|., data = exdat) # The 'data' argument is required with '.' ## Not run: strucParseFormula (y ~ x|.) ## End(Not run)