tally.data {RelativeRisk} | R Documentation |
Tallies data into strata according to the values of environmental variables.
tally.data(sName,fName,indexName,data,sigDigits=2)
sName |
The quoted name of the data column containing either success counts, or values in (0,1) to be pooled: 1 is success. |
fName |
If present, the quoted name of the data column containing the failure counts matching the success counts in sName. |
indexName |
The quoted name of the index variable for the counts in sName: 1 is success. |
data |
A data frame, whose columns contain the values of environmental variables defining the strata. |
sigDigits |
The number of significant digits used to compare numerical environmental variable levels. |
This function may be used before performing a GLM analysis
for binary data to prepare a matrix of success, failure counts
and associated environmental variable values. tally.data()
will be called by est.rr()
if doTally
in est.rr()
is set to TRUE
. For large data sets, tally.data()
may take a while, so it is best to run it
separately from est.rr()
if possible.
The strata are created by pooling together all data rows with equivalent sets of environmental variables. Numerical values are
compared after rounding to sigDigits
. The first set of
environmental variables in a stratum is taken as typical and then output as
the stratum's description in the output matrix.
A list with elements (log, Y, X). log will contain a comment. Y will contain a matrix, with columns (success,failure) containing counts for each stratum. The matrix X will contain the values of the environmental variables for the stratum.
All columns in data will be used to define the
strata. Redundant columns should be eliminated before calling
this function. if tally.data()
is called from est.rr()
,
redundant columns not appearing in the formula will be
discarded automatically.
Bob Wheeler bwheelerg@gmail.com
Please cite this program as follows:
Wheeler, R.E. (2009). tally.data RelativeRisk. The R project for statistical computing http://www.r-project.org/
data(TitanicMat) ad<-tally.data("count",indexName="survived",data=TitanicMat) ad$Y ad$X