wolffd@0: function ndx = subv2indKPM(siz, subv)
wolffd@0: % SUBV2IND Like the built-in sub2ind, but the subscripts are given as row vectors.
wolffd@0: % ind = subv2ind(siz,subv)
wolffd@0: %
wolffd@0: % siz can be a row or column vector of size d.
wolffd@0: % subv should be a collection of N row vectors of size d.
wolffd@0: % ind will be of size N * 1.
wolffd@0: %
wolffd@0: % Example:
wolffd@0: % subv = [1 1 1;
wolffd@0: %         2 1 1;
wolffd@0: %         ...
wolffd@0: %         2 2 2];
wolffd@0: % subv2ind([2 2 2], subv) returns [1 2 ... 8]'
wolffd@0: % i.e., the leftmost digit toggles fastest.
wolffd@0: %
wolffd@0: % See also IND2SUBV.
wolffd@0: 
wolffd@0: 
wolffd@0: if isempty(subv)
wolffd@0:   ndx = [];
wolffd@0:   return;
wolffd@0: end
wolffd@0: 
wolffd@0: if isempty(siz)
wolffd@0:   ndx = 1;
wolffd@0:   return;
wolffd@0: end
wolffd@0: 
wolffd@0: [ncases ndims] = size(subv);
wolffd@0: 
wolffd@0: %if length(siz) ~= ndims
wolffd@0: %  error('length of subscript vector and sizes must be equal');
wolffd@0: %end
wolffd@0: 
wolffd@0: if all(siz==2)
wolffd@0:   %rbits = subv(:,end:-1:1)-1; % read from right to left, convert to 0s/1s
wolffd@0:   %ndx = bitv2dec(rbits)+1; 
wolffd@0:   twos = pow2(0:ndims-1);
wolffd@0:   ndx = ((subv-1) * twos(:)) + 1;
wolffd@0:   %ndx = sum((subv-1) .* twos(ones(ncases,1), :), 2) + 1; % equivalent to matrix * vector
wolffd@0:   %ndx = sum((subv-1) .* repmat(twos, ncases, 1), 2) + 1; % much slower than ones
wolffd@0:   %ndx = ndx(:)';
wolffd@0: else
wolffd@0:   %siz = siz(:)';
wolffd@0:   cp = [1 cumprod(siz(1:end-1))]';
wolffd@0:   %ndx = ones(ncases, 1);
wolffd@0:   %for i = 1:ndims
wolffd@0:   %  ndx = ndx + (subv(:,i)-1)*cp(i);
wolffd@0:   %end
wolffd@0:   ndx = (subv-1)*cp + 1;
wolffd@0: end
wolffd@0: 
wolffd@0: %%%%%%%%%%%
wolffd@0: 
wolffd@0: function d = bitv2dec(bits)
wolffd@0: % BITV2DEC Convert a bit vector to a decimal integer
wolffd@0: % d = butv2dec(bits)
wolffd@0: %
wolffd@0: % This is just like the built-in bin2dec, except the argument is a vector, not a string.
wolffd@0: % If bits is an array, each row will be converted.
wolffd@0: 
wolffd@0: [m n] = size(bits);
wolffd@0: twos = pow2(n-1:-1:0);
wolffd@0: d = sum(bits .* twos(ones(m,1),:),2);
wolffd@0: