I am reading parameters from an Excel file but am having trouble using them
in tapply. Here is a mini-version of my problem.
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sorted <- data.frame(c("Single","Single","Double","Double","Double",
"Triple"),
c(324.5, 435.3, 568.3, 345.4, 143.5, 563.5))
colnames(sorted) <- c("ITEM","PRICE")
attach(sorted)
sMean <- tapply(PRICE,ITEM,mean) # works but cannot use column names
directly
# since reading them from an Excel file
into
# a parameter file
Pname <- c("PRICE")
Iname <- c("ITEM")
parameter <- data.frame(Pname,Iname) # This mimics reading the specific
column names
# from Excel
# Now I want to indirectly reference the PRICE and ITEM columns but this
does
# not work as expected
sMean2 <- tapply(parameter$Pname, parameter$Iname, mean)
--
Any assistance would be greatly appreciated.
__________________________
*Barry E. King, Ph.D.*
Chief Modeler
Qualex Consulting Services, Inc.
[email protected]
O: (317)940-5464
M: (317)507-0661
__________________________
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