HealthKit composite data for HealthKit development tutorials

HealthKit composite data for HealthKit development Tutorials

composite data is data composed of composite units and values. The so-called composite Unit is the unit for multiplication, division and other units obtained, such as m/s,lb· ft and so is the compound unit. This section will explain these composite data.

HealthKit'smultiply the resulting composite data

in physics, we may have been exposed to similar lb · ft (torque unit, torque is a special torque that causes the object to rotate.) ) such a unit. This unit can be seen as a compound unit multiplied by two units. Developers who want to use this compound unit in their own programs first need to create this unit. Creating such a unit requires the use of the Unitmultipliedbyunit (_:) method, which has the following syntax:

• Func Unitmultipliedbyunit (_ unit:hkunit!), hkunit!

where the parameters Unit : Used to specify the units to be multiplied.

The example 2-44 : Hkunit-unitmultipliedbyunit "The following shows the torque of the generator in the car, to" lbs . feet "is the unit. The code is as follows:

• Import UIKit

• Import HealthKit

• Class Viewcontroller:uiviewcontroller {

• Override Func Viewdidload () {

• Super.viewdidload ()

• Additional setup after loading the view, typically from a nib.

• & nbsp         var footunit = Hkunit.footunit ()                                                                                           // Create length units

• & nbsp       var poundunit=hkunit.poundunit ()                                                                                   // Create mass units

• var unitmultipliedbyunit=footunit.unitmultipliedbyunit (poundunit) // multiply the resulting compound units

• var myforce=hkquantity (Unit:unitmultipliedbyunit, doublevalue:100)

• println (" the torque of the generator in the car is:\ (myforce)")

• }

• ......

• }

When you run the program, you see the following effect.

• the torque of the generator in the car is: lb · ft

HealthKit'sdivide the resulting composite data

in mathematical calculations, we often encounter m/S such a unit. This unit is divided into two units. If the developer wants to use this unit in their own code. You first need to use the Unitdividedbyunit (_:) method to create this unit, with the following syntax:

• Func Unitdividedbyunit (_ unit:hkunit!), hkunit!

where the parameters _ Unit used to specify the unit, which is used as a divisor.

The example 2-45 : Hkunit-unitdividedbyunit The following shows the speed at which the user runs, in meters / seconds "is the unit. The code is as follows:

• Import UIKit

• Import HealthKit

• Class Viewcontroller:uiviewcontroller {

• Override Func Viewdidload () {

• Super.viewdidload ()

• Additional setup after loading the view, typically from a nib.

• & nbsp       Let meters = Hkunit.meterunit ()                                                                       // Create length units

• Let seconds = hkunit.secondunit ()// Create a time unit

• Let Meterspersecond = meters.unitdividedbyunit (seconds)// dividing the resulting compound units

• Let Speed=hkquantity (Unit:meterspersecond, Doublevalue:2)

• println (" Xiao Ming runs at speed:\")

• }

• ......

• }

When you run the program, you see the following effect.

• Xiao Ming runs at the speed of: 2 m/s

HealthKit'scompound data consisting of units and integers in the sub-square

in terms of volume and area, we will use the M3 , m2 such units. This unit is a composite unit composed of units and the sub-party of integers. If developers want to create such a unit, they need to use the Unitraisedtopower (_:) method, which has the following syntax:

• Func Unitraisedtopower (_ Power:int), hkunit!

where the parameters Power is an integer that is used to specify the secondary side.

The example 2-46 : Hkunit-unitraisedtopower "The volume of the basin is shown below , in cubic meters." the code is as follows:

• Import UIKit

• Import HealthKit

• Class Viewcontroller:uiviewcontroller {

• Override Func Viewdidload () {

• Super.viewdidload ()

• Additional setup after loading the view, typically from a nib.

• var meters = Hkunit.meterunit ()

• var cubicmeter=meters.unitraisedtopower (3)// A compound unit of a unit and a sub-square of integers

• var pool=hkquantity (Unit:cubicmeter, doublevalue:100)

• println (" Pool size:\ (Pool)")

• }

• ......

• }

When you run the program, you see the following effect.

• the volume of the pool is: m^3

HealthKit'sa compound unit of reciprocal composition

1/s This unit is a "Hertz" unit, which represents the 1 the frequency at which a cycle process occurs within a second time interval. A unit similar to 1/s is composed of the reciprocal of a unit. If you want to use this unit in your program, you need to use the reciprocalunit () method. the function of the reciprocalunit () method is to construct a new compound unit by the inverse of the unit. Its grammatical form is as follows:

• Func reciprocalunit ()-hkunit!

The example 2-47 : Hkunit-reciprocalunit The following shows the 1 The frequency at which a cycle process occurs within the seconds interval to " 1/ seconds "is the unit. The code is as follows:

• Import UIKit

• Import HealthKit

• Class Viewcontroller:uiviewcontroller {

• Override Func Viewdidload () {

• Super.viewdidload ()

• Additional setup after loading the view, typically from a nib.

• var seconds = Hkunit.secondunit ()

• var secondsinverse = seconds.reciprocalunit () // a compound unit consisting of the reciprocal

• var frequency=hkquantity (Unit:secondsinverse, doublevalue:50)

• println (" the frequency of a cycle process occurring within a 1-second interval is:\ (Frequency)")

• }

• ......

• }

When you run the program, you see the following effect.

• in the 1 the frequency at which a cycle process occurs within a second interval is: 1/s

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HealthKit composite data for HealthKit development tutorials