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 tape = require( 'tape' );
  var isnan = require( '@stdlib/math/base/assert/is-nan' );
  var randu = require( '@stdlib/random/base/randu' );
  var EPS = require( '@stdlib/constants/math/float64-eps' );
  var abs = require( '@stdlib/math/base/special/abs' );
  var acosh = require( './../lib' );
  
  
  // FIXTURES //
  
  var largerPositive = require( './fixtures/julia/larger_positive.json' );
  var largePositive = require( './fixtures/julia/large_positive.json' );
  var mediumPositive = require( './fixtures/julia/medium_positive.json' );
  var hugePositive = require( './fixtures/julia/huge_positive.json' );
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.true( typeof acosh, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function computes the hyperbolic arccosine on the interval [1.0,3.0]', function test( t ) {
  	var expected;
  	var delta;
  	var tol;
  	var x;
  	var y;
  	var i;
  
  	x = mediumPositive.x;
  	expected = mediumPositive.expected;
  
  	for ( i = 0; i < x.length; i++ ) {
  		y = acosh( x[i] );
  		if ( y === expected[ i ] ) {
  			t.equal( y, expected[ i ], 'x: '+x[i]+'. E: '+expected[i] );
  		} else {
  			delta = abs( y - expected[i] );
  			tol = 1.0 * EPS * abs( expected[i] );
  			t.ok( delta <= tol, 'within tolerance. x: '+x[i]+'. y: '+y+'. E: '+expected[i]+'. tol: '+tol+'. Δ: '+delta+'.' );
  		}
  	}
  	t.end();
  });
  
  tape( 'the function computes the hyperbolic arccosine on the interval [3.0,28.0]', function test( t ) {
  	var expected;
  	var delta;
  	var tol;
  	var x;
  	var y;
  	var i;
  
  	x = largePositive.x;
  	expected = largePositive.expected;
  
  	for ( i = 0; i < x.length; i++ ) {
  		y = acosh( x[i] );
  		if ( y === expected[ i ] ) {
  			t.equal( y, expected[ i ], 'x: '+x[i]+'. E: '+expected[i] );
  		} else {
  			delta = abs( y - expected[i] );
  			tol = 1.0 * EPS * abs( expected[i] );
  			t.ok( delta <= tol, 'within tolerance. x: '+x[i]+'. y: '+y+'. E: '+expected[i]+'. tol: '+tol+'. Δ: '+delta+'.' );
  		}
  	}
  	t.end();
  });
  
  tape( 'the function computes the hyperbolic arccosine on the interval [28.0,100.0]', function test( t ) {
  	var expected;
  	var delta;
  	var tol;
  	var x;
  	var y;
  	var i;
  
  	x = largerPositive.x;
  	expected = largerPositive.expected;
  
  	for ( i = 0; i < x.length; i++ ) {
  		y = acosh( x[i] );
  		if ( y === expected[ i ] ) {
  			t.equal( y, expected[ i ], 'x: '+x[i]+'. E: '+expected[i] );
  		} else {
  			delta = abs( y - expected[i] );
  			tol = 1.0 * EPS * abs( expected[i] );
  			t.ok( delta <= tol, 'within tolerance. x: '+x[i]+'. y: '+y+'. E: '+expected[i]+'. tol: '+tol+'. Δ: '+delta+'.' );
  		}
  	}
  	t.end();
  });
  
  tape( 'the function computes the hyperbolic arccosine for huge values', function test( t ) {
  	var expected;
  	var delta;
  	var tol;
  	var x;
  	var y;
  	var i;
  
  	x = hugePositive.x;
  	expected = hugePositive.expected;
  
  	for ( i = 0; i < x.length; i++ ) {
  		y = acosh( x[i] );
  		if ( y === expected[ i ] ) {
  			t.equal( y, expected[ i ], 'x: '+x[i]+'. E: '+expected[i] );
  		} else {
  			delta = abs( y - expected[i] );
  			tol = 1.0 * EPS * abs( expected[i] );
  			t.ok( delta <= tol, 'within tolerance. x: '+x[i]+'. y: '+y+'. E: '+expected[i]+'. tol: '+tol+'. Δ: '+delta+'.' );
  		}
  	}
  	t.end();
  });
  
  tape( 'the function returns `NaN` if provided `NaN`', function test( t ) {
  	var v = acosh( NaN );
  	t.equal( isnan( v ), true, 'returns NaN' );
  	t.end();
  });
  
  tape( 'the function returns `NaN` if provided value less than `1`', function test( t ) {
  	var v;
  	var i;
  
  	for ( i = 0; i < 1e3; i++ ) {
  		v = -(randu()*1.0e6) + (1-EPS);
  		t.equal( isnan( acosh( v ) ), true, 'returns NaN when provided '+v );
  	}
  	t.end();
  });
  