I want to find the index my agent has in its population (named dullieses), which lives in my Main-agent.
I want to find one of my dullieses-agent via one of its variables (DullyID) which, in this example, shall be equal to my counter variable. Both are of type int.
I have tried the following to no avail:
int i = 0;
for ( i = 0; i < dullieses.size(); i++){
if (Main.dullieses(i).DullyID == counter){
traceln("I found myself! I have the index " + i);
break;
}
}
Error code: Cannot make a static reference to the non-static method dullies(int) from type Main.
How can I find my agent in my population and find its index?
I think you're probably already in main and don't need to add Main..
Anyway, I would recommend using:
Dully d = findFirst( dullieses, d -> d.ID == counter );
d.variable = 10;
I used variable and 10 as random examples, but this should give you the idea. Also replace Dully with whatever your agent type name is.
You don't need to use a custom ID parameter in your agents (at least not for what you're doing here).
All agents in a population have the getIndex function which returns their index in the population. Just be wary that, if you remove agents from a population, their indices will change (so you can't, for example, use their index as a unique ID for them in that case).
Related
I am working on agent-based modelling where I have created a function that generates a random point inside a region and then converts that point to agent. However, when I use this function later, the points don't give me a proper location on the map for further computation. I want to know what I am doing wrong? Or how can this be improved.
The return type for the function is ArrayList
ArrayList<DeliveryHouse> House = new ArrayList<DeliveryHouse>();
int i;
Point p;
DeliveryHouse h;
for(i=0;i<packagesC2C;i++)
{
p = main.Region2.randomPointInside();
h = main.deliveryHouse.setLocation(p);
House.add(i, h);
};
return House;
The major problem I see with your code is that you are not initializing the agent "h" but pointing it to one agent you have at main which means you keep changing its location in the loop and it will only reflect the last location. The array list you created will have multiple references to same agent instead of one agent per location.
If you want to create an agent per location you need to create an agent population called "deliveryHouses" of the agent type "DeliveryHouse" and change your code to the following. Note that the population will have all the agents so you do not need any output from the function.
int i;
Point p;
for(i=0;i<packagesC2C;i++)
{
DeliveryHouse h = main.add_deliveryHouses();
p = main.Region2.randomPointInside();
h.setLocation(p);
}
I am trying to use system verilog constraint solver to solve the following problem statement :
We have N balls each with unique weight and these balls need to be distributed into groups , such that weight of each group does not exceed a threshold ( MAX_WEIGHT) .
Now i want to find all such possible solutions . The code I wrote in SV is as follows :
`define NUM_BALLS 5
`define MAX_WEIGHT_BUCKET 100
class weight_distributor;
int ball_weight [`NUM_BALLS];
rand int unsigned solution_array[][];
constraint c_solve_bucket_problem
{
foreach(solution_array[i,j]) {
solution_array[i][j] inside {ball_weight};
//unique{solution_array[i][j]};
foreach(solution_array[ii,jj])
if(!((ii == i) & (j == jj))) solution_array[ii][jj] != solution_array[i][j];
}
foreach(solution_array[i,])
solution_array[i].sum() < `MAX_WEIGHT_BUCKET;
}
function new();
ball_weight = {10,20,30,40,50};
endfunction
function void post_randomize();
foreach(solution_array[i,j])
$display("solution_array[%0d][%0d] = %0d", i,j,solution_array[i][j]);
$display("solution_array size = %0d",solution_array.size);
endfunction
endclass
module top;
weight_distributor weight_distributor_o;
initial begin
weight_distributor_o = new();
void'(weight_distributor_o.randomize());
end
endmodule
The issue i am facing here is that i want the size of both the dimentions of the array to be randomly decided based on the constraint solution_array[i].sum() < `MAX_WEIGHT_BUCKET; . From my understanding of SV constraints i believe that the size of the array will be solved before value assignment to the array .
Moreover i also wanted to know if unique could be used for 2 dimentional dynamic array .
You can't use the random number generator (RNG) to enumerate all possible solutions of your problem. It's not built for this. An RNG can give you one of these solutions with each call to randomize(). It's not guaranteed, though, that it gives you a different solution with each call. Say you have 3 solutions, S0, S1, S2. The solver could give you S1, then S2, then S1 again, then S1, then S0, etc. If you know how many solutions there are, you can stop once you've seen them all. Generally, though, you don't know this beforehand.
What an RNG can do, however, is check whether a solution you provide is correct. If you loop over all possible solutions, you can filter out only the ones that are correct. In your case, you have N balls and up to N groups. You can start out by putting each ball into one group and trying if this is a correct solution. You can then put 2 balls into one group and all the other N - 2 into a groups of one. You can put two other balls into one group and all the others into groups of one. You can start putting 2 balls into one group, 2 other balls into one group and all the other N - 4 into groups of one. You can continue this until you put all N balls into the same group. I'm not really sure how you can easily enumerate all solutions. Combinatorics can help you here. At each step of the way you can check whether a certain ball arrangement satisfies the constraints:
// Array describing an arrangement of balls
// - the first dimension is the group
// - the second dimension is the index within the group
typedef unsigned int unsigned arrangement_t[][];
// Function that gives you the next arrangement to try out
function arrangement_t get_next_arrangement();
// ...
endfunction
arrangement = get_next_arrangement();
if (weight_distributor_o.randomize() with {
solution.size() == arrangement.size();
foreach (solution[i]) {
solution[i].size() == arrangement[i].size();
foreach (solution[i][j])
solution[i][j] == arrangement[i][j];
}
})
all_solutions.push_back(arrangement);
Now, let's look at weight_distributor. I'd recommend you write each requirement in an own constraint as this makes the code much more readable.
You can shorten you uniqueness constraint that you wrote as a double loop to using the unique operator:
class weight_distributor;
// ...
constraint unique_balls {
unique { solution_array };
}
endclass
You already had a constraint that each group can have at most MAX_WEIGHT in it:
class weight_distributor;
// ...
constraint max_weight_per_group {
foreach (solution_array[i])
solution_array[i].sum() < `MAX_WEIGHT_BUCKET;
}
endclass
Because of the way array sizes are solved, it's not possible to write constraints that will ensure that you can compute a valid solution using simple calls randomize(). You don't need this, though, if you want to check whether a solution is valid. This is due to the constraints on array sizes in the between arrangement and solution_array.
Try this.!
class ABC;
rand bit[3:0] md_array [][]; // Multidimansional Arrays with unknown size
constraint c_md_array {
// First assign the size of the first dimension of md_array
md_array.size() == 2;
// Then for each sub-array in the first dimension do the following:
foreach (md_array[i]) {
// Randomize size of the sub-array to a value within the range
md_array[i].size() inside {[1:5]};
// Iterate over the second dimension
foreach (md_array[i][j]) {
// Assign constraints for values to the second dimension
md_array[i][j] inside {[1:10]};
}
}
}
endclass
module tb;
initial begin
ABC abc = new;
abc.randomize();
$display ("md_array = %p", abc.md_array);
end
endmodule
https://www.chipverify.com/systemverilog/systemverilog-foreach-constraint
I am using a collection to represent available trucks in a system. I am using a 1 or 0 for a given index number, using a 1 to say that indexed truck is available. I am then trying to assign that index number to a customer ID. I am trying to randomly select an available truck from those listed as available. I am getting an error saying the left-hand side of an assignment must be a variable and highlighting the portion of the code reading Available_Trucks() = 1. This is the code:
agent.ID = randomWhere(Available_Trucks, Available_Trucks() = 1);
The way you are doing it won't work... randomWhere when applied to a collection of integers, will return the element of the collection (in this case 1 or 0).
So doing
randomWhere(Available_Trucks,at->at==1); //this is the right synthax
will return 1 always since that's the value of the number chosen in the collection. So what you need is to get the index of the number of the collection that is equal to 1. But you will have to create a function to do that yourself... something like this (probably not the best way but it works: agent.ID=getRandomAvailbleTruck(Available_Trucks);
And the function getRandomAvailbleTruck will take as an argument a collection (arrayList probably).. it will return -1 if there is no availble truck
int availableTrucks=count(collection,c->c==1);
if(availableTrucks==0) return -1;
int rand=uniform_discr(1,availableTrucks);
int i=0;
int j=0;
while(i<rand){
if(collection.get(j)==1){
i++;
if(i==rand){
return j;
}
}
j++;
}
return -1;
Now another idea is to instead of using 0 and 1 for the availability, you can use correlative numbers: 1,2,3,4,5 ... etc and use a 0 if it's not available. For instance if truck 3 is not availble, the array will be 1,2,0,4,5 and if it's available it will be 1,2,3,4,5.
In that case you can use
agent.ID=randomTrue(available_trucks,at->at>0);
But you will get an error if there is no available truck, so check that.
Nevertheless, what you are doing is horrible practice... And there is a much easier way to do it if you put the availability in your truck if your truck is an agent...
Then you can just do
Truck truck=randomWhere(trucks,t->t.available==1);
if(truck!=null)
agent.ID=truck.ID;
I'm still having troubles with AnyLogic...I'm developing an epidemic SIRS model and I want to define my own network.
In particular, I have this matrix that defines the daily average number of contacts between age class
and therefore I want every agent to establish contact with other agents according to this matrix...it is driving me crazy :S
AgeClass is a parameter calculated with the following function
I thought to setup an event that occurs once at the beginning with the following code
Now I am saying "connect n times to a random agent"...what I want to say is "connect n times to a random agent with AgeClass k" is there a way to do so?
thanks for the support!
ps when I write int i = AgeClass i takes the value of the parameter AgeClass of the agent that is running the code, right? So i it will be different for different agents?
Probably, you have already found a solution. Here a way to do it:
Regarding age, you don't need that big if/else if sequence. Just do something like this:
int ageClass = 0; // a variable of agents
ageClass = (int) floor(age / 5.0);
if (age >= 70.0 ) ageClass == 14; // just to be sure that max class is 14
return ageClass;
Regarding the network. I would create a function named setup, so that you can put it in agent actions, on startup, e.g. setup();
You can create a link to agents object at the agent level (Person in my code, I use a connection object named contacts). The function would be something like:
// loop through age groups
for (int i = 0; i < network[0].length; i++) {
ArrayList<Person> ageGroupPeople = new ArrayList<Person>();
for (Person p : population ) {
if ( p.ageClass == i ) { ageGroupPeople.add(p) } \\ create pool of potential alters by age
}
\\ create network per agent
for (Person ego : population ) {
for (int k = 0; k < poisson(network[ego.ageClass][i]); k++) {
Person alter = randomFrom(ageGroupPeople);
if ( ego != alter ) { ego.contacts.connectTo(alter);}
}
}
I haven't checked the code and how slow might be, it is just one way to do it.
In AnyLogic, you can represent a matrix as two-dimensional Java array:
http://help.anylogic.com/topic/com.xj.anylogic.help/html/code/Arrays.html
After initializing the matrix, you may define custom contact network using the element 'Link to agents':
http://help.anylogic.com/topic/com.xj.anylogic.help/html/agentbased/Link.html
include "globals.mzn";
%Data
time_ID = [11,12,13,14,15];
eventId = [0011, 0012, 0013, 0021, 0022, 0031, 0041, 0051, 0061, 0071];
int:ntime = 5;
int:nevent = 10;
set of int: events =1..nevent;
set of int: time = 1..ntime;
array[1..nevent] of int:eventId;
array[1..nevent] of var time:event_time;
array[1..ntime] of int:time_ID;
solve satisfy;
constraint
forall(event in eventId)(
exists(t in time_ID)(
event_time[event] = t ));
output[ show(event_time) ];
I'm trying to assign times to an event using the code above.
But rather than randomly assign times to the events, it returns an error " array access out of bounds"
How can I make it select randomly from the time array?
Thank you
The error was because you tried to assign the index 11 (the first element in eventId array) in "event_time" array.
The assigment of just 1's is correct since you haven't done any other constraints on the "event_time" array. If you set the number of solutions to - say - 3 you will see other solutions. And, in fact, the constraint as it stand now is not really meaningful since it just ensures that there is some assignment to the elements in "event_time", but this constraint is handled by the domain of "event_time" (i.e. that all indices are in the range 1..ntime).