{
    "contents" : "require(plyr)\nmtcars\nvroom<-data.frame(mtcars)\nView(vroom)\nvroom2<-vroom[order(vroom$cyl,vroom$disp,vroom$wt),]\nvroom2$cars<-rownames(vroom2)\nrownames(vroom2)<-NULL\nvroom3<-vroom2[c(\"cyl\",\"disp\",\"hp\",\"wt\",\"mpg\",\"cars\")]\n\nvroom4<-as.matrix(vroom3)\nvmean<-tapply(X=vroom3$mpg,INDEX=vroom3$cyl,FUN=mean)\nvsd<-tapply(X=vroom3$mpg, INDEX=vroom3$cyl,FUN=sd)\nvquant<-tapply(X=vroom3$mpg, INDEX=vroom3$cyl, FUN=quantile,c(0.025,0.975))\nvroom4<-as.data.frame(cbind(vmean,vsd,vquant))\nvroom5<-cut(vroom3$hp,breaks=3)\nlevels(vroom5)<-c(\"gutless\",\"passible\",\"macho\")\nvroom6<-cbind(vroom3,vroom5)\ntapply(X=vroom6$mpg, INDEX=list(vroom6$vroom5,vroom6$cyl),FUN=mean)\n",
    "created" : 1413311375392.000,
    "dirty" : false,
    "encoding" : "UTF-8",
    "folds" : "",
    "hash" : "2947191244",
    "id" : "46CE599E",
    "lastKnownWriteTime" : 1413315961,
    "path" : "~/R/IntroR/lecture6.R",
    "project_path" : "lecture6.R",
    "properties" : {
        "tempName" : "Untitled1"
    },
    "source_on_save" : false,
    "type" : "r_source"
}