How do I sort values of string variable based on the order of frequencies

[Thong Nguyen]

I mean, in my dataset, I have a string variable X, which has 10 values such as a, b, c, etc.
When I use tab command, it gives the result
X freq.
a 10
b 5
c 20
And I want to sort values of X, from highest to lowest, in order to have the following result
X freq.
c 20
a 10
b 5


Can I do that in stata? Thank you all in advance

[daniel klein]

The results are equivalent. Do you want a different output or a different sort order of the dataset?

Best
Daniel

[Thong Nguyen]

Let me make my problem clearer for you! When using the sort command. It will sort the variable based on the alphabetical order of values of variable, not on order of frequency of values. In fact, I have a list of diseases, which is coded before and entried in excell. And I want to obtain the top ten diseases that occur most frequently in the dataset. Thanks for your help!

[Thong Nguyen]

List of diseases is so long and if I create a new variable and then replace, label, it will take a lot of time!

[Nick Cox]

-tabulate, sort-

-ssc desc groups-
-ssc inst groups-

[daniel klein]

Nick answered the question (I think). If you want the frequencies in a dataset

contract X
sort _freq

Best
Daniel

[Thong Nguyen]

Thanks for your help but I don't know how to make it right.
I have a string variable X
X has 4 groups, such as a b c d
and I have different number of observations with each groups.
How do I list groups orderly based on the count of observations in the study (from highest to lowes).

[Thong Nguyen]

Finally, I get it. Thank you all!