DISTINCT Values

I strongly miss a function to return the number of DISTINCT values 
existent in a given cell range. To my knowledge, this functionality is 
missing in every spreadsheet application, although most of the research 
involves such analysis.

I would be further interested  to perform some operations using these 
distinct values.

Functions:
DISTINCT( 'cell_range', AS.TEXT = TRUE, IGNORE.CASE = TRUE)
returns number of distinct strings in the cell range


DISTINCT( 'cell_range', AS.TEXT = FALSE, TOLERANCE = 0)
returns number of different values
DISTINCT( 'cell_range', AS.TEXT = FALSE, TOLERANCE = 0.5, ORDER = 
"ASCENDING")
returns number of different values; values within TOLERANCE are 
considered EQUAL
  - values are ranked first using the specified ORDER
  - IF( x[i] is within TOLERANCE of x[i-1]), the 2 values are considered 
equal
DISTINCT( 'cell_range', AS.TEXT = FALSE, TOLERANCE = '5%', ORDER = 
"ASCENDING")
returns number of different values; values within TOLERANCE are 
considered EQUAL
  - values are ranked first using the specified ORDER
  - IF( x[i] is within TOLERANCE of x[i-1]), the 2 values are considered 
equal
  - the absolute value for TOLERANCE is computed as x[i-1] * TOLERANCE


DISTINCT( 'cell_range', AS.TEXT = FALSE, 'cell_range2')
returns number of different values within 'cell_range'
  - 'cell_range2' describes the bounds/intervals used for splitting the 
initial data (i.e. for splitting 'cell_range')
  - the values within 'cell_range2' are ranked
  - IF any value from 'cell_range' < MIN('cell_range2') => this is first 
group
  - any value from 'cell_range' is within
        RANKED(cell_range2)[1]
        RANKED(cell_range2)[2] => next group
  - ...
  - any value from 'cell_range' > MAX('cell_range2') => this is the last 
group

Of course, DISTINCT() is just one aspect of the analysis. Actually, I am 
more interested in doing specific calculations based on these distinct 
groups (like SUM(), COUNT(), ...). I will describe such calculations in 
a later post.

Sincerely,

Leonard Mada