parfor中的递增数组?

有两件事在代码中不起作用:

for k = j+1:particles

在parfor中,嵌套循环应具有固定的边界。

2) pop(ind)

具体的 在这种情况下,顺序并不重要(但matlab不够聪明,不知道这一点)。

解决方案,线性化:

%Dummy data
numBins = 20;
binWidth = 2.5;
particles = 10;
coords = rand(10,2)*40;

%Initialization
pop = zeros(1,numBins);

parfor j=1:particles
    r1  = coords(j,:)
    r2  = coords((j+1):end,:)          
    d   = sqrt(sum([r1-r2].^2,2)) % compute each norm at the same time !
    pop = pop + histcounts(ceil(d/binWidth),0:numBins) 
end

function pop = hist_comp(pop,j,particles,coords,binWidth)
  r1 = coords(j,:);
  for k=j+1:particles
      r2 = coords(k,:);
      d = norm(r1-r2);
      ind = ceil(d/binWidth);
      pop(ind) = pop(ind) + 1;
  end
end

numBins = 20;
binWidth = 2.5;
particles = 10;
coords = rand(10,2)*5;
pop = zeros(1,numBins);


f = @(pop,j) hist_comp(pop,j,particles,coords,binWidth);

parfor j=1:particles
  pop = f(pop,j);
end