function cfloorn( z, n ) {
	return new Complex128( floorn( real( z ), n ), floorn( imag( z ), n ) );
}
Rounds each component of a double-precision complex floating-point number to the nearest multiple of `10^n` toward negative infinity.

@param {Complex128} z - complex number
@param {integer} n - integer power of 10
@returns {Complex128} result

@example
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );

// Round components to 2 decimal places:
var v = cfloorn( new Complex128( -3.141592653589793, 3.141592653589793 ), -2 );
// returns <Complex128>

var re = real( v );
// returns -3.15

var im = imag( v );
// returns 3.14

// If n = 0, `cfloorn` behaves like `cfloor`:
v = cfloorn( new Complex128( 9.99999, 0.1 ), 0 );
// returns <Complex128>

re = real( v );
// returns 9.0

im = imag( v );
// returns 0.0

// Round components to the nearest thousand:
v = cfloorn( new Complex128( 12368.0, -12368.0 ), 2 );
// returns <Complex128>

re = real( v );
// returns 12300

im = imag( v );
// returns -12400

v = cfloorn( new Complex128( NaN, NaN ), 2 );
// returns <Complex128>

re = real( v );
// returns NaN

im = imag( v );
// returns NaN