function createStream1( d1, d2 ) {
		return new RandomStream( d1, d2, opts );
	}
Returns a readable stream for generating pseudorandom numbers drawn from an F distribution.

@private
@param {PositiveNumber} d1 - degrees of freedom
@param {PositiveNumber} d2 - degrees of freedom
@throws {TypeError} `d1` must be a positive number
@throws {TypeError} `d2` must be a positive number
@throws {TypeError} options argument must be an object
@throws {TypeError} must provide valid options
@throws {Error} must provide a valid state
@returns {RandomStream} Stream instance