Conversion of column matrix into a vector without duplicate

A = matrix(c("a","b","c","d","e","u","v",rep("x",3)),5,2,byrow=F)

unique(A[, 2])

Large Matrix into a vector

mx <- matrix(rnorm(100,1:100),10,10)
vec <- c(mx)

or

vec <- c(as.matrix(mx))

or

dim(mx) <- NULL

Fill a matrix with vectors of different lengths

v <- c(1,1,2,3,4,6)
binc <- function(x){
l <- sum(x)+1
y <- c(1,rep(0,l-1))
for (i in x) y <- y+c(rep(0,i),y)[1:l]
}
out <- lapply(1:length(v), function(i) binc(v[1:i]))
nout <- max(sapply(out, length))
sapply(out, function(x) c(x, rep(0, nout - length(x))))