The structure of the PLRP files is as follows:


number of customers
number of available depots
number of serviced days		number of periods on the horizon

coordinates for the customers (x and y)	total demand over the horizon	visit frequency

coordinates for the depots 	capacity of the depot	setup cost of the depot

vehicle capacity	setup cost	number of available vehicles


0 or 1 (0 means that the costs are integer - 1 that costs are real)

number of possible frequency 	total number of possible combinations

for each frequency:
frequency 	total number of possible combinations for the frequency
list of the combinations

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To calculate the matrix distance (or the cost to link any 2 points A and B in the graph), we use the mathematical formula:

sqrt( (xA-xB)² + (yA-yB)² )

The results are stored in a float variable (in C language) if the costs are real (code 1)
The result is multiplied by 100 and truncked to be stored in an integer variable if the costs are interger (code 0).

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To calculate the demand for customer c on each day of combination r (if the frequency is not equal to 1):

let Dc = total demand of customer c over the horizon
let d(c,jr,r) = demand of customer c on day jr of combination r

Thus:

PeriodDem = Dc /(number of periods on the horizon);
DemTot = 0 ;
jr1 = last day of the combination r;
do
{
	jr = day before jr1 in the combination r
	d(c,jr1,r) = PeriodDem * (jr1-jr);
	if(d(c,jr1,r) = 0) d(c,jr1,r)=1;
	DemTot= DemTot + d(c,jr1,r);
	jr1 = jr
}until(jr = first day of the combination r)

d(c,jr,r) = Dc - DemTot;