Ever wonder how to generate data within R?

**c(…)**generic function to combine arguments with the default forming a vector; with recursive=TRUE descends through lists combining all elements into one vector**from:to**generates a sequence; “:” has operator priority; 1:4 + 1 is “2,3,4,5”**seq(from,to**) generates a sequence by= specifies increment; length=specifies desired length**seq(along=x)**generates 1, 2, …, length(along); useful for for loops**rep(x,times)**replicate x times; use each= to repeat “each” element of x each times; rep(c(1,2,3),2) is 1 2 3 1 2 3;**rep(c(1,2,3),each=2)**is 1 1 2 2 3 3**data.frame(…)**create a data frame of the named or unnamed arguments; data.frame(v=1:4,ch=c(“a”,”B”,”c”,”d”),n=10);- shorter vectors are recycled to the length of the longest
**list(…)**create a list of the named or unnamed arguments;**list(a=c(1,2),b=”hi”,c=3i)**;**array(x,dim=)**array with data x; specify dimensions like**dim=c(3,4,2)**; elements of x recycle if x is not long enough**matrix(x,nrow=,ncol=)**matrix; elements of x recycle**factor(x,levels=)**encodes a vector x as a factor**gl(n,k,length=n*k,labels=1:n)**generate levels (factors) by specifying the pattern of their levels; k is the number of levels, and n is the number of replications**expand.grid()**a data frame from all combinations of the supplied vectors or factors**rbind(…)**combine arguments by rows for matrices, data frames, and others**cbind(…)**id. by columns