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.