text: /**
  * @license Apache-2.0
  *
  * Copyright (c) 2018 The Stdlib Authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *    http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
  
  'use strict';
  
  // MODULES //
  
  var isNonNegativeInteger = require( '@stdlib/math/base/assert/is-nonnegative-integer' );
  var constantFunction = require( '@stdlib/utils/constant-function' );
  var factoryGamma = require( '@stdlib/stats/base/dists/gamma/cdf' ).factory;
  
  
  // MAIN //
  
  /**
  * Returns a function for evaluating the cumulative distribution function (CDF) for an Erlang distribution with shape parameter `k` and rate parameter `lambda`.
  *
  * @param {NonNegativeInteger} k - shape parameter
  * @param {PositiveNumber} lambda - rate parameter
  * @returns {Function} CDF
  *
  * @example
  * var cdf = factory( 2, 0.1 );
  * var y = cdf( 12.0 );
  * // returns ~0.337
  *
  * y = cdf( 8.0 );
  * // returns ~0.191
  */
  function factory( k, lambda ) {
  	if ( !isNonNegativeInteger( k ) ) {
  		return constantFunction( NaN );
  	}
  	return factoryGamma( k, lambda );
  }
  
  
  // EXPORTS //
  
  module.exports = factory;
  