toMarginalAggr.m

function [ni, nir] = toMarginalAggr(sn, ind, state_i, K, Ks, space_buf, space_srv, space_var) %#ok<INUSD>
% TOMARGINALAGGR Compute aggregate marginal distributions for a specific node
%
% [NI, NIR] = TOMARGINALAGGR(SN, IND, STATE_I, K, KS, SPACE_BUF, SPACE_SRV, SPACE_VAR)
%
% @brief Computes aggregate marginal job counts from state information without phase details
%
% This function provides a simplified version of toMarginal that computes
% aggregate job counts per node and per class, without considering individual
% service phases. It is more efficient when phase-level detail is not required.
%
% @param sn Network structure or Network object
% @param ind Node index to extract marginal information for
% @param state_i Global state matrix or vector
% @param K Vector of population for each class
% @param Ks Matrix of populations per chain and class
% @param space_buf Buffer space configuration
% @param space_srv Service space configuration  
% @param space_var Variable space configuration
%
% @return ni Total jobs in node IND (aggregate across all classes)
% @return nir Jobs per class in node IND [vector: classes]
 
% Copyright (c) 2012-2026, Imperial College London
% All rights reserved.
 
if ~isstruct(sn) % the input can be a Network object too
    sn=sn.getStruct();
end
% ind: node index
ist = sn.nodeToStation(ind);
%isf = sn.nodeToStateful(ind);
R = sn.nclasses;
if ~sn.isstation(ind) && sn.isstateful(ind) % if stateful node
    ni = sum(state_i(1:(end-sum(sn.nvars(ind,:)))));
    nir = state_i(1:(end-sum(sn.nvars(ind,:))));
    return
end
 
if nargin < 4
    K = sn.phasessz(ist,:);
end
    if nargin < 5
    Ks = sn.phaseshift(ist,:);
end
 
if nargin < 8
    space_var = state_i(:,(end-sum(sn.nvars(ind,:))+1):end); % server state
    space_srv = state_i(:,(end-sum(K)+1):(end-sum(sn.nvars(ind,:))));
    space_buf = state_i(:,1:(end-sum(K)));
end
 
nir = zeros(size(state_i,1),R); % class-r jobs in service
for r=1:R
    for k=1:K(r)
        nir(:,r) = nir(:,r) + space_srv(:,Ks(r)+k);
    end
end
switch sn.sched(ist)
    case SchedStrategy.EXT
        for r=1:R
            nir(:,r) = Inf;
        end
    case SchedStrategy.FCFS
        for r=1:R
            nir(:,r) = nir(:,r) + sum(space_buf==r,2); % class-r jobs in station
        end
    case SchedStrategy.HOL
        for r=1:R
            nir(:,r) = nir(:,r) + sum(space_buf==r,2); % class-r jobs in station
        end
    case SchedStrategy.LCFS
        for r=1:R
            nir(:,r) = nir(:,r) + sum(space_buf==r,2); % class-r jobs in station
        end
    case SchedStrategy.SIRO
        for r=1:R
            nir(:,r) = nir(:,r) + space_buf(:,r); % class-r jobs in station
        end
    case SchedStrategy.SEPT
        for r=1:R
            nir(:,r) = nir(:,r) + space_buf(:,r); % class-r jobs in station
        end
    case SchedStrategy.LEPT
        for r=1:R
            nir(:,r) = nir(:,r) + space_buf(:,r); % class-r jobs in station
        end
        %otherwise % possibly other stateful nodes
        % no-op
end
 
for r=1:R
    if isnan(sn.rates(ist,r)) && sn.nodetype(ind) ~= NodeType.Place % if disabled
        nir(:,r) = 0;
    end
end
 
ni = sum(nir,2); % total jobs in station
end