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 isnan = require( '@stdlib/math-base-assert-is-nan' );
  var isInfinite = require( '@stdlib/math-base-assert-is-infinite' );
  var pow = require( '@stdlib/math-base-special-pow' );
  var floor = require( '@stdlib/math-base-special-floor' );
  var ceil = require( '@stdlib/math-base-special-ceil' );
  var log10 = require( '@stdlib/math-base-special-log10' );
  var MAX_EXP = require( '@stdlib/constants-float64-max-base10-exponent' );
  var MIN_EXP_SUBNORMAL = require( '@stdlib/constants-float64-min-base10-exponent-subnormal' );
  var NINF = require( '@stdlib/constants-float64-ninf' );
  
  
  // MAIN //
  
  /**
  * Rounds a numeric value to the nearest power of `10` toward negative infinity.
  *
  * @param {number} x - input value
  * @returns {number} rounded value
  *
  * @example
  * var v = floor10( 3.141592653589793 );
  * // returns 1.0
  *
  * @example
  * var v = floor10( 9.0 );
  * // returns 1.0
  *
  * @example
  * var v = floor10( -0.314 );
  * // returns -1.0
  */
  function floor10( x ) {
  	var sign;
  	var p;
  	if (
  		isnan( x ) ||
  		isInfinite( x ) ||
  		x === 0.0
  	) {
  		return x;
  	}
  	if ( x < 0 ) {
  		x = -x;
  		sign = -1.0;
  	} else {
  		sign = 1.0;
  	}
  	// Solve the equation `10^p = x` for `p`:
  	p = log10( x );
  
  	// Determine a power of 10 which rounds the input value toward negative infinity:
  	if ( sign === 1.0 ) {
  		p = floor( p );
  	} else {
  		p = ceil( p );
  	}
  	// Handle underflow:
  	if ( p <= MIN_EXP_SUBNORMAL ) {
  		return sign * 0.0; // sign-preserving
  	}
  	// Handle overflow:
  	if ( p > MAX_EXP ) {
  		return NINF;
  	}
  	return sign * pow( 10.0, p );
  }
  
  
  // EXPORTS //
  
  module.exports = floor10;
  