Math

Most mathematical operations are supported by vif.

Calculations on float numbers might not work the same way as a real plc.

vif-sim uses the IEEE 754 float types similar to IEC standard.

It is a tough subject in computer science, to avoid sacrificing too much performance vif-sim does not use any arbitrary-precision library except the built-in rust formatter.

Just Remember the digits representation of a float number is not the real number in memory.

For example, it's often impossible to guarantee equality between 2 float types if both numbers have too many digits, unless we use Lt / Gt operators:

const fb = new Fb({
    interface: {
        static: {
            MyReal: new Real(0.9),
            MyLReal: new LReal(0.9)
        }
    },
    body() {
        return [
            // Will fail
            new UnitTest("Real tan strictly eq", new Tan(this.static.MyReal), "=", 1.260158),

            new UnitTest("Real tan >=", new Tan(this.static.MyReal), ">=", 1.260157),
            new UnitTest("Real tan <=",  new Tan(this.static.MyReal), "<=", 1.260159),

            new UnitTest("LReal tan >=", new Tan(this.static.MyLReal), ">=", 1.26015821755032),
            new UnitTest("LReal tan <=", new Tan(this.static.MyLReal), "<=", 1.26015821755034)
        ]
    }
})

However, if the number is rational, Equality will works fine.

const fb = new Fb({
    interface: {
        static: {
            MyReal: new Real(0.9256),
            MyLReal: new LReal(0.9256987)
        }
    },
    body() {
        return [
            new UnitTest("Real strictly eq", this.static.MyReal, "=", 0.9256),
            new UnitTest("LReal strictly eq", this.static.MyLReal, "=", 0.9256987),
        ]
    }
})

Abs

Returns the absolute value of a number.

import {Abs} from "#math"

const MyAbs = new Abs(50)

Acos

Returns the ArcCos of any REAL.

import {ACos} from "#math"

const MyACos = new ACos(0.5)

ASin

Returns the ArcSin of any REAL.

import {ASin} from "#math"

const MyASin = new ASin(0.5)

ATan

Returns the ArcTan of any REAL.

import {ATan} from "#math"

const MyATan = new ATan(0.5)

Ceil

Rounds a REAL to the higher nearest integer.

import {Ceil} from "#math"

const MyCeil = new Ceil(0.2)

Cos

Returns the Cos of any REAL.

import {Cos} from "#math"

const MyCos = new Cos(0.5)

Exp

Returns the exponential of any REAL.

import {Cos} from "#math"

const MyCos = new Cos(0.5)

Floor

Rounds any REAL to the lowest nearest integer.

import {Floor} from "#math"

const MyFloor = new Floor(0.5)

Fract

Returns the fractional part of any REAL.

import {Floor} from "#math"

const MyFloor = new Floor(0.5)

Ln

Returns the natural logarithm part of any REAL.

import {Ln} from "#math"

const MyLn = new Ln(0.5)

Round

Rounds any REAL to the nearest integer.

import {Round} from "#math"

const MyRound = new Round(0.6)

Sin

Returns the Sin of any REAL.

import {Sin} from "#math"

const MySin = new Sin(0.5)

Sqr

Returns the square of any number (basically x*x).

import {Sin} from "#math"

const MySin = new Sin(0.5)

Sqrt

Returns the square root of any number.

import {Sin} from "#math"

const MySin = new Sin(0.5)

Tan

Returns the Tan of any REAL.

import {Tan} from "#math"

const MyTan = new Tan(0.5)

Trunc

Returns the integer part of any REAL.

import {Trunc} from "#math"

const MyTrunc = new Trunc(0.5)