isunique¶

Purpose¶

Returns a 1 if the data contains all unique observations, otherwise returns a 0.

Format¶

ret = isunique(x[, varlist])¶

Parameters:

x (matrix or dataframe) – data
varlist (string array) – Optional, list of variables to include in the check. Default is across all variables.

Returns:

ret (scalar) – 1 if x contains unique observations across the specific varlist, otherwise 0.

Examples¶

Example 1¶

new;

// Create file name with full path
fname = getGAUSSHome() $+ "examples/tips2.dta";

// Load the dataframe
tips2 = loadd(fname, "id + total_bill + tip + cat(sex) + cat(smoker) + cat(day) + cat(time) + size");

// Check if all observations of the id variable are unique
if isunique(tips2, "id");
  print "ID variable is unique.";
else;
  print "ID variable contains duplicates.";
endif;

After the above code the printed output is

ID variable contains duplicates.

Example 2¶

Now we will check to see if just the id is duplicated or if all variables are duplicated.

// Check if dataframe has duplicates observations
// across all variables
if isunique(tips2);
  print "Dataframe is unique.";
else;
  print "Dataframe contains duplicates.";
endif;

After the above code the printed output is

Dataframe contains duplicates.