github.com/jingcheng-WU/gonum@v0.9.1-0.20210323123734-f1a2a11a8f7b/unit/unitexample_test.go (about)

     1  // Copyright ©2017 The Gonum Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package unit_test
     6  
     7  import (
     8  	"fmt"
     9  
    10  	"github.com/jingcheng-WU/gonum/unit"
    11  )
    12  
    13  func ExampleNew() {
    14  	// Create an angular acceleration of 3 rad/s^2
    15  	accel := unit.New(3.0, unit.Dimensions{unit.AngleDim: 1, unit.TimeDim: -2})
    16  	fmt.Println(accel)
    17  
    18  	// Output: 3 rad s^-2
    19  }
    20  
    21  func ExampleNewDimension() {
    22  	// Create a "trees" dimension
    23  	// Typically, this should be used within an init function
    24  	treeDim := unit.NewDimension("tree")
    25  	countPerArea := unit.New(0.1, unit.Dimensions{treeDim: 1, unit.LengthDim: -2})
    26  	fmt.Println(countPerArea)
    27  
    28  	// Output: 0.1 tree m^-2
    29  }
    30  
    31  func Example_horsepower() {
    32  	// One mechanical horsepower ≡ 33,000 ft-lbf/min.
    33  	foot := unit.Length(0.3048)
    34  	pound := unit.Mass(0.45359237)
    35  
    36  	gravity := unit.Acceleration(9.80665)
    37  	poundforce := pound.Unit().Mul(gravity)
    38  
    39  	hp := ((33000 * foot).Unit().Mul(poundforce)).Div(unit.Minute)
    40  	fmt.Println("1 hp =", hp)
    41  
    42  	watt := unit.Power(1)
    43  	fmt.Println("W is equivalent to hp?", unit.DimensionsMatch(hp, watt))
    44  
    45  	// Output:
    46  	//
    47  	// 1 hp = 745.6998715822701 kg m^2 s^-3
    48  	// W is equivalent to hp? true
    49  }