[UPDATE] use validate.io modules

lib/index.js

@@ -30,7 +30,8 @@
 
 // MODULES //
 
-var isInteger = require( 'validate.io-integer' );
+var isNumber = require( 'validate.io-number-primitive' ),
+	isNonNegativeInteger = require( 'validate.io-nonnegative-integer' );
 
 
 // LOGSPACE //
@@ -50,16 +51,16 @@ function logspace( a, b, len ) {
 		tmp,
 		d;
 
-	if ( typeof a !== 'number' || a !== a ) {
+	if ( !isNumber( a ) ) {
 		throw new TypeError( 'logspace()::invalid input argument. Exponent of start value must be numeric. Value: `' + a + '`.' );
 	}
-	if ( typeof b !== 'number' || b !== b ) {
+	if ( !isNumber( b ) ) {
 		throw new TypeError( 'logspace()::invalid input argument. Exponent of stop value must be numeric. Value: `' + b + '`.' );
 	}
 	if ( arguments.length < 3 ) {
 		len = 10;
 	} else {
-		if ( !isInteger( len ) || len < 0 ) {
+		if ( !isNonNegativeInteger( len ) ) {
 			throw new TypeError( 'logspace()::invalid input argument. Length must be a positive integer. Value: `' + len + '`.' );
 		}
 		if ( len === 0 ) {

package.json

@@ -43,7 +43,8 @@
     "url": "https://github.com/compute-io/logspace/issues"
   },
   "dependencies": {
-    "validate.io-integer": "^1.0.1"
+    "validate.io-nonnegative-integer": "^1.0.0",
+    "validate.io-number-primitive": "^1.0.0"
   },
   "devDependencies": {
     "chai": "2.x.x",