refer to levels of variables

[#1]

Dear Community

How do I perform a count of the levels of a variable?

In R i can type length(levels(x)). 

example: the species of bacteria are levels of the variable "species" 

best,

[#2]

If you want unique values in a list or table column here are some functions that will help.  The first one is for a list:

/*
Function Name: get_unique_values
Description: Find the unique values in a list.  Uses an associative array
Arguments:
in_list		List to get unique values for
*/
Get_unique_values = Function( {in_list},
      {Default Local}, 
      tmp = [=> 0]; 
      Insert Into( tmp, in_list ); 
      tmp << get keys; 
); 

For a table column:

/* Function Name	Get_Unique_Values_col
Description:	Get the unique values for a column.  For example:

	Indications
	------------
	AAAAA
	BBBBB
	AAAAA
	CCCCC
	CCCCC

unique_list = get_unique_values_col (:Indications)

will return {"AAAAA", "BBBBB", "CCCCC"}

Arguments:
dtcol		column descriptor to calculate unique values for
*/
Get_Unique_Values_col = Function( {dtcol},{default local},
// Eval/expr trickery to get this to work.
	eval(eval expr(
		Summarize(unique_list = By(expr(dtcol)))));
	unique_list;
);

[#3 · Accepted solution]

If you prefer an interactive solution, use Tables > Summary. Put the column you want as a Group variable and click OK. The number of rows in the resulting data table is the number of levels.

OR

Make the variable you want an ordinal or nominal variable. Use Analyze > Distribution. 

[#4]

Thank you very much

In the histogram there is a line with "levels" , gives me exactly what i need.

still, at the risk of whining, the numbers of levels may be in the hundreds and it is cumbersome to scroll past the frequency table. I imagine there should be an easier way to find out how many unique values are in a column...

[#5]

Then use the Tables > Summary approach. You may get a table with hundreds of rows, but the row panel at the bottom will tell you how many rows are in the table.

You can also look to see if this suggestion was put into the JMP Wish List. If it is there, kudo it to cast your vote to add this feature. If you don't find it there, then add it.

[#6]

Hi thanks for this interesting answer. I could not get it to work though. it is undoubtedly due to my lack of skills. 

[#7 · Accepted solution]

'Cols > Columns Viewer' gives this kind of output with 'Show Summary':

[#8]

Thank you!!

This is the best most direct way to find the number of levels.

It is a little "hidden" but at least it gives me what I need