Counting cases in a vector
Sometimes we need the count values cases in a given vector. One way I found to do the task is by check one condition and then counting TRUE or FALSE cases in the result vector. For example:
aL <- a<=3
that will result in vector values of:  TRUE TRUE TRUE TRUE TRUE FALSE FALSE FALSE TRUE
will give you the count of TRUE in the vector i.e. the amount of cases with values larger or equal to 3
How beautiful could it be!