To choose a random code from a list of codes, type:

To choose a random code from the codes present in a column, type:

Occasionally you might want to set a random code into a column, perhaps because the code in that column is incorrect. To do this, write:

cvar is the column into which one of the codes ‘p’ is to go. For example:

will place one of the codes 1 through 5 in column 115.

Alternatively, you can use rpunch with another C-variable, thus:

Once this statement has been executed, column 115 will contain one of the codes present in column 120.