refactor: add floating-point guard

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

Author: kgryte

lib/node_modules/@stdlib/stats/strided/dpcorrwd/src/main.c

@@ -18,6 +18,7 @@
 
 #include "stdlib/stats/strided/dpcorrwd.h"
 #include "stdlib/math/base/special/sqrt.h"
+#include "stdlib/math/base/special/clamp.h"
 #include "stdlib/blas/base/shared.h"
 #include "stdlib/strided/base/stride2offset.h"
 
@@ -166,6 +167,7 @@ double API_SUFFIX(stdlib_strided_dpcorrwd_ndarray)( const CBLAS_INT N, const dou
 	double sy;
 	double sx;
 	double C;
+	double r;
 
 	if ( N <= 0 ) {
 		return 0.0 / 0.0; // NaN
@@ -197,5 +199,6 @@ double API_SUFFIX(stdlib_strided_dpcorrwd_ndarray)( const CBLAS_INT N, const dou
 	}
 	sx = stdlib_base_sqrt( M2x/N );
 	sy = stdlib_base_sqrt( M2y/N );
-	return ( C/N ) / ( sx*sy ); // Note: why all the dividing by `N`? To avoid overflow.
+	r = ( C/N ) / ( sx*sy ); // Why all the dividing by `N`? To avoid overflow.
+	return stdlib_base_clamp( r, -1.0, 1.0 ); // Guard against accumulated floating-point errors resulting in |r| > 1
 }