MathWit entry/demo course - Math0

Create the first class :(run the following code and see if you get the same output, then modify and make your own example)

 > testClass <- setClass("testClass", slots = c(x="numeric", y="numeric")) > test.class <- testClass(x = 10:1, y = 1:10 ) > setValidity("testClass", function(object){object@x <= object@y+100 && length(object@x)>=1 && length(object@y)>=1}) Class "testClass" [in ".GlobalEnv"] Slots: Name: x y Class: numeric numeric > validObject(test.class) [1] TRUE > plus.testClass <- function(object){object@x + object@y} > plus <- function(object){object@plus} > setGeneric("plus") [1] "plus" > setMethod(plus,signature=c("testClass"),definition=plus.testClass) [1] "plus" attr(,"package") [1] ".GlobalEnv" > showMethods("plus") Function: plus (package .GlobalEnv) object="ANY" object="testClass" > plus(test.class) [1] 11 11 11 11 11 11 11 11 11 11 # Define generic function in your way, for example, redefine summary function > setMethod("summary",signature="testClass",definition=function(object){print(paste(object@x, object@y, sep="~", collapse=" , "))}) [1] "summary" > summary(test.class) [1] "10~1 , 9~2 , 8~3 , 7~4 , 6~5 , 5~6 , 4~7 , 3~8 , 2~9 , 1~10" The following code is optional, read and play if you wish: > setClass("TSeries", representation(data="numeric", start="POSIXct",end="POSIXct") ) > testClass <- new("TSeries",data=c(1:10),start=as.POSIXct("06/18/2014 0:00:00",tz="GMT",format="%m%d%Y% %H:%M:%S"),end=as.POSIXct("06/18/2014 0:01:01",tz="GMT",format="%m%d%Y% %H:%M:%S")) > setValidity("TSeries", function(object){object@start <= object@end && length(object@start)==1 && length(object@end)==1}) Class "TSeries" [in ".GlobalEnv"] Slots: Name: data start end Class: numeric POSIXct POSIXct .

Next, create a new class "AddVariablesTest" based on the class: testClass. We have two ways to achieve the same goal. See the following code and output: > setClass("AddVariablesTest", representation(varA="numeric",varB="character"),contains = "testClass") > anObj <- new("AddVariablesTest",x = 5:10, y = 1:6, varA=99, varB="Some information here ....") > anObj An object of class "AddVariablesTest" Slot "varA": [1] 99 Slot "varB": [1] "Some information here ...." Slot "x": [1] 5 6 7 8 9 10 Slot "y": [1] 1 2 3 4 5 6 > setClass("partA", representation(varA="numeric", varB="character") ) > setClass("partAandB", contains = c("testClass","partA") ) > anObjB <- new("partAandB",x = 5:10, y = 1:6, varA=99, varB="Some information here ....") > anObjB An object of class "partAandB" Slot "x": [1] 5 6 7 8 9 10 Slot "y": [1] 1 2 3 4 5 6 Slot "varA": [1] 99 Slot "varB": [1] "Some information here ...." > setClass("anotherCategory", representation(varC ="character", varB="character")) > # Now create a virtual class that is a super class of partA and anotherCategory > setClassUnion("testUnion", c("partA","anotherCategory")) > is(anObjB,"testUnion") [1] TRUE > is(anObjB,"partAandB") [1] TRUE

Please avoid the following keywords for slot names: "class" , "comment" , "dim" , "dimnames" , "names" , "row.names" and "tsp" . SetIS function can be used to define inheritance relationship.