function FN = randFN(nstate,NN,d,estr)
%if ~exist('d','var')
%  d=1;
%end
if ~exist('estr','var')
  exact = 0;
else
  exact = strcmp(estr,'exact');
end
FN = {};
if (NN<0)
  NN = -NN;
  NNj = NN;
else
  NNj = 1:NN;
end
for j=NNj
  FN{j} = randF(nstate,j,d,exact);
end
return

function F = randF(nstate,lenseq,d,exact)
% F is a random function $\X^n \to [0,1]$ that sat. ibd w/c=1
X = list_all_ind(repmat(nstate,1,lenseq));
K = 10;
%K = 1;
%K = lenseq;
%F(1) = 0;
PROGstart(size(X,1),'generating randF...');
for i=1:size(X,1)
%for i=2:size(X,1)
  good = 0;
  while ~good
    F(i) = K*rand;
    if exact
      F(i) = round(F(i));
    end
    good = 1;
    for j = 1:i-1
      good = goodij(X,F,i,j,d,exact);
      if ~good, break, end;
    end
  end
  %fprintf('randF: done %d of %d \n',i,size(X,1));
  PROGupdate(i);
end
PROGend;
return

function b = goodij(X,F,i,j,d,exact)
x = X(i,:);
y = X(j,:);
if (length(find(x~=y))==1)
  if exact
    b = (abs(F(i)-F(j))==1);
  else
    b = (abs(F(i)-F(j))<=d);
  end
else
  b = 1;
end
return