sinus.js

// this computes a sinusoidal curve from midnight to midnight, oscillating between 5 and 6 mmol/l

const { number } = require("mathjs");

if (!Date.now) {
    Date.now = function() { return new Date().getTime(); }
}
//timestamp in milliseconds;
console.log ('timestamp in milliseconds',Date.now())

// timestamp in days;
console.log ('timestamp in days',Date.now() / 86400000)

// timestamp in days rounded;
console.log ('timestamp in days rounded',Math.floor(Date.now() / 86400000))

//timestamp in fraction of a day;
console.log ('timestamp in fraction of a day',(Date.now()/86400000) - (Math.floor(Date.now() / 86400000)))

//fraction of a day in hours;
console.log ('fraction of a day in hours',((Date.now()/86400000) - (Math.floor(Date.now() / 86400000))) * 24)

//fraction of a day in hours adding 2 for UTC+2;
console.log ('fraction of a day in hours adding 2 for UTC+2',(((Date.now()/86400000) - (Math.floor(Date.now() / 86400000))) * 24) + 2)

// time of the day in hours - decimals, not minutes
var hours = ((((Date.now()/86400000) - (Math.floor(Date.now() / 86400000))) * 24) + 2);
console.log ('time of the day in hours - using decimals, not minutes: ',hours.toFixed(2));

// express minutes also;
var hoursabs = Math.floor(hours);
var minutes = (hours - hoursabs) * 60;
console.log ('express minutes in minutes also:', minutes.toFixed(), 'minutes');

// time of the day in 2 pi cycle;
var daycycle = ((hours * Math.PI) / 12);
console.log ('time of the day in 2 pi cycle',daycycle.toFixed(2));

// time of the day in 360 deg cycle;
var daycycledeg = ((hours * 360) / 24);
console.log ('time of the day in 360 deg cycle', daycycledeg.toFixed(2));

// value of the sin function according to hours, oscillating from -1 to +1;
var SIN = Math.sin(daycycledeg * Math.PI / 180); 
console.log ('value of the sin function according to hours, oscillating from -1 to +1: ', SIN.toFixed(2));

// value of the sin function oscillating between 0 and 2;
var SINinterm = (Math.sin(daycycledeg * Math.PI / 180) + 1); 
console.log ('value of the sin function oscillating between 0 and 2: ', SINinterm.toFixed(2));





//==========================================================================================
// value of the sin function oscillating around 1, +/- 20 %
//==========================================================================================
var sinFunction = (Math.sin(daycycledeg * Math.PI / 180));
var SINcorr = (sinFunction/5) + 1; 
console.log ('value of the sin function oscillating around 1, +/- 20 %, starting from 1 and ending in 1: ', SINcorr.toFixed(2));
console.log ("When the time of day is " + hours.toFixed() + " hours and " + minutes.toFixed() + " minutes, the sinusoidal value is: " + SINcorr.toFixed(3)); 



//==========================================================================================
// value of the cos function oscillating around 1, +/- 20 %
//==========================================================================================
var cosinFunction = (Math.cos(daycycledeg * Math.PI / 180));
var COScorr = (cosinFunction/5) +1; 
console.log ('value of the cos function oscillating around 1, +/- 0.5, starting from 1.5 and ending in 1.5: : ', COScorr.toFixed(2));
console.log ("When the time of day is " + hours.toFixed() + " hours and " + minutes.toFixed() + " minutes, the cosinusoidal value is: " + COScorr.toFixed(3)); 


//==========================================================================================
// make the json file
//==========================================================================================

var sincurves = {sinus : SINcorr, cosinus : COScorr};
var sinusCurvesString = JSON.stringify(sincurves);

var fs = require('fs');
fs.writeFile("./files/sinuscurves.json", sinusCurvesString, function(err, result) {
    if(err) console.log('error', err);
});