Are there some Emacs' packages which can be used for analysing the frequency of the characters and the words used in the current buffer.
As a particular example it would be interesting to have a mechanism for sorting the frequency of the characters of a given buffer.
For example if the content of a buffer is
This is a test. the sorted frequency will be as below.
t 3 s 3 i 2 a 1 e 1 h 1 . 1