Check Distribution

Function to check distribution of unique elements in a vector or matrix.

Description

Function to check distribution of unique elements in a vector or matrix.

result=checkdistribution(x)

'result' would be a 2-column matrix, column 1 indicating which unique
numbers are present (in ascending manner), column 2 indicating how many
of them. Sum of column 2 gives total number of elements in x.
Also, plots the result, no. of apperance vs. unique elements.
It is useful for integer vector/matrix with repeatations. For effective
use in float vector/matrix, one has to round the float vector/matrix
before checking the distribution.

Example: result=checkdistribution([1,1,2,2,2,3,3,3,3,10])
result =

     1 2
     2 3
     3 4
    10 1

i.e., there are two 1's, three 2's, four 3's and one 10 in x.

If x is a string, the result includes the ASCII values of the letters,
and their countings. ASCII table can be found: www.asciitable.com

Example: result=checkdistribution('apple')
result =

    97 1
   101 1
   108 1
   112 2

i.e., one 'a'(97), 'e'(101), 'l'(108), and two 'p'(112).

• MATLAB release: MATLAB 7.3 (R2006b)

[Jos x@y.z]

Well done, as it includes a readable help section, H1 line, examples. This makes it user friendly!
It lacks some checks on the inputs, and the same can be achieved using HISTC:

[ua,ia,ia] = unique(a) ;
result = [ua(:) histc(ia(:),1:numel(ua))] ;

which can deal with FP properly as well. Furthermore, you should omit the plot, as it is not really that user friendly (it creates a possible unwanted new figure or changes my current one).

I rate this as 4 stars, since it is really a (too) simple algorithm, but 1) it does what it says it does, and 2) the author should be credited for his efforts in writing a user-friendly interface!