frequency of values of a matrix or vector
[m]=tabul(X [,order])
vector or matrix (of real or complex numbers or strings)
(optional) a character equal to "d" or "i" (default value "d")
a 2 columns matrix (if X
is a numerical vector or matrix) or
a list with 2 members (if X
is a string vector or matrix).
This function computes the frequency of values of
the components of a vector or matrix X
of numbers or
string characters :
then m
is a two column matrix who contains in
the first column the distinct values of X
and in the other column the number of occurrences
of those values (m(i,2) is the number of occurrences
of m(i,1)).
then m
is a list whose first member is a
string (column) vector composed with the distinct
values of X
and the second member is a
(column) vector whose components are the number of
occurrences of those values ( m(i)(2) is the number
of occurrences of the string m(i)(1) ).
The optional parameter order
must be "d" or "i" (by default
order="d") and gives the order (decreasing or increasing) the distinct
values of X will be sorted.
n = 50000; X = grand(n,1,"bin",70,0.5); m = tabul(X,"i"); clf() plot2d3(m(:,1), m(:,2)/n) xtitle("empirical probabilities of B(70,0.5)") | ![]() | ![]() |
// computes the occurrences of words of the license of scilab text = read(SCI+"/COPYING",-1,1,"(A)"); // read the scilab license bigstr = strcat(text," "); // put all the lines in a big string sep = [" " "," "." ";" "*" ":" "-" """"]; // words separators words = tokens(bigstr, sep); // cut the big string into words m = tabul(words); // computes occurrences of each word [occ , p] = gsort(m(2)); // sort by decreasing frequencies results = [m(1)(p) string(occ)] // display result | ![]() | ![]() |
Wonacott, T.H. & Wonacott, R.J.; Introductory Statistics, fifth edition, J.Wiley & Sons, 1990.