expand.grid
Create a Data Frame from All Combinations of Factors
Description
Create a data frame containing all combinations of the values in the
input vectors.
Usage
expand.grid(..., KEEP.OUT.ATTRS = TRUE, stringsAsFactors = TRUE)
Arguments
| ... |
vector and factor arguments, typically with no repeated values.
The arguments can be named, in which case the names are used in
the result. Default variable names are "Var" followed by an integer.
If a single list is supplied, then its components (and names) are
treated as the ... arguments.
|
| KEEP.OUT.ATTRS |
A logical value.
If TRUE, the default, the returned data.frame will have an out.attrs attribute,
which contains information about the input vectors of this call to expand.grid.
Otherwise, the out.attrs attributed will not be attached to the output.
|
| stringsAsFactors |
A logical value. If TRUE, the default, convert character
arguments to factors whose levels are the unique strings in
the argument (in the order in which they were encountered
in the character vector).
|
Value
A data frame containing all combinations of the values in the ... arguments.
There will be a column for each input argument and a row
for each combination. Values in the first column cycle the
fastest, followed by the second, etc.
If KEEP.OUT.ATTRS = TRUE, the result contains an attribute,
out.attrs, which is a list of attributes dim and
dimnames, which are suitable for turning
the result into an array.
See Also
Examples
fit <- lm(uptake ~ Type + Treatment, data=CO2)
grid <- with(CO2, expand.grid(Type=unique(Type), Treatment=unique(Treatment)))
cbind(grid, "Predicted Uptake"=predict(fit, newdata=grid))