test: update descriptions

Signed-off-by: Athan <kgryte@gmail.com>

Author: kgryte

lib/node_modules/@stdlib/stats/base/ndarray/dmeanpn/test/test.js

@@ -85,7 +85,7 @@ tape( 'the function calculates the arithmetic mean of a one-dimensional ndarray'
 	t.end();
 });
 
-tape( 'if provided an empty vector, the function returns `NaN`', function test( t ) {
+tape( 'if provided an empty ndarray, the function returns `NaN`', function test( t ) {
 	var x;
 	var v;
 
@@ -97,7 +97,7 @@ tape( 'if provided an empty vector, the function returns `NaN`', function test(
 	t.end();
 });
 
-tape( 'if provided a vector containing a single element, the function returns that element', function test( t ) {
+tape( 'if provided an ndarray containing a single element, the function returns that element', function test( t ) {
 	var x;
 	var v;