I want to set up params.arrival_rate every 3 hours of sim_time. This comprises a day but I would like to extend to N days. So, each time slot of 3 hours (in the code below is in minutes) of this N day, params.arrival_rate takes a value. Any optimal function to do so?

My actual code looks like this:

    if(sim_time >= 0 && sim_time <= 180) //00:00 - 03:00 
    {
        params.arrival_rate = 10; 
    }
    else if(sim_time > 180 && sim_time <= 360) //03:00-06:00
    {
        params.arrival_rate = 9; 
    }
    else if(sim_time > 360 && sim_time <= 540) //06:00-09:00 
    {
        params.arrival_rate = 10.5; 
    }
    else if(sim_time > 540 && sim_time <= 720) //09:00-12:00
    {
        params.arrival_rate = 12; 
    }
    else if(sim_time > 720 && sim_time <= 900) //12:00-15:00 
    {
        params.arrival_rate = 11.5; 
    }
    else if(sim_time > 900 && sim_time <= 1080) //15:00-18:00 
    {
        params.arrival_rate = 11; 
    }
    else if(sim_time > 1080 && sim_time <= 1260) //18:00-21:00 
    {
        params.arrival_rate = 10.5; 
    }
    else if(sim_time > 1260 && sim_time <= 1440) //21:00-24:00   
    {
        params.arrival_rate = 9;
    }
    else //by default 
    {
        params.arrival_rate = 9;   
    }

Many thanks.

CodePudding user response：

Assuming you want the same pattern every day, it suffices to take the time modulo 1440 minutes:

int day_time = sim_time % 1440;
int day_no   = sim_time / 1440;

Now you can use day_time to get the time in the current day and use that to calculate params.arrival_rate. day_no will contain the day number (starting from 0).

As a further enhancement, consider using an array for your arrival rates instead of a long if-elseif chain:

const double arrival_rates[] = { 10, 9, 10.5, 12, 11.5, 11, 10.5, 9 };
params.arrival_rate = arrival_rates[day_time / (3 * 60)];

The calculation inside the brackets will round down the day_time to the start of the nearest three-hour block.