Simulation reference

This page contains a complete list of available features you can use when you create your own simulation. You may also like to see the simulation framework on GitHub.

Pre-declared variables

JavaScript usually requires you to declare variables before using them. For convenience, the framework declares the variables n, asleep_at and awake_at by default:

// this is OK because the framework pre-declares the variables:
for ( n=0; n<365; ++n ) {
  asleep_at = n*days +  6*hours;
  awake_at  = n*days + 14*hours;
  add_diary_entry({ asleep_at, awake_at });
}

// if you use another variable name, make sure to declare it:
var x;
for ( x=0; x<365; ++x ) {
  asleep_at = x*days +  6*hours;
  awake_at  = x*days + 14*hours;
  add_diary_entry({ asleep_at, awake_at });
}

Specify Dates

Simulations calculate dates by adding a number of milliseconds to a start date. For readability, the framework provides the constants seconds, minutes, hours and days as aliases for the equivalent number of milliseconds. You can also set the start date with the start_at() function:

// set the start date and time:
start_at("2020-03-25T18:00:00Z");

// specify times literally or using the constants provided:
var time = 1; // one millisecond
var time = 1000; // one second
var time = 1*seconds; // also one second
var time = 1*minutes; // 60*seconds
var time = 1*hours; // 60*minutes
var time = 1*days; // 24*hours

Add a diary entry

The add_diary_entry function takes an options argument, which is an object containing the following values:

• asleep_at or begin - the time when the entry began (in milliseconds since the start date)
• awake_at or end - the time when the entry ended (in milliseconds since the start date)
• status - your status during the time described by the entry (default: asleep)

// these two are identical:
add_diary_entry({
  asleep_at: 1000, // one second past the start date
  awake_at: 8*60*60*1000, // 8 hours past the start date
});
add_diary_entry({
  begin: 1_seconds, // one second past the start date
  end  : 8*hours, // 8 hours past the start date
  status: 'asleep',
});

// specify an alarm clock woke you up:
add_diary_entry({
  begin: 8*hours, // 8 hours past the start date
  end  : 8*hours, // 8 hours past the start date
  status: 'alarm',
});

The list of valid record types is stored in DiaryStandardRecordStatus in Standard/engine.js.

Miscellaneous

The framework also provides the normal_distribution() function (a random number with a bell curve centred on 0) and day_of_week() (the English name of the date at a specified time). You can also use any JavaScript functionality to generate models:

// Use various functions to calculate a time:
var time = 4*days + 2*normal_distribution()*hours + Math.random()*minutes;

switch ( day_of_week(time) ) {
  case "Sunday":
    // ...
    break;
  case "Monday":
    // ...
    break;
  case "Tueday":
    // ...
    break;
  case "Wednesday":
    // ...
    break;
  case "Thursday":
    // ...
    break;
  case "Friday":
    // ...
    break;
  case "Saturday":
    // ...
    break;
}