Error using loop over grid (Help)

I wrote this code using Matlab R2014a in order to loop through a virtual grid:

clear, clc

format long g

load rN_Tang.txt

load aN_Tang.txt

c=aN_Tang(:,:); f=rN_Tang(:,:);

DepthsA=-c(:,3);

LongitudeA=c(:,1);

DepthsR=-f(:,3);

LongitudeR=f(:,1);

 for I=724:747;
     J=2:8;
        k=1:length(aN_Tang);
        l=1:length(rN_Tang);
         if ((I<LongitudeA(k)<=I+1 & J<DepthsA(k)<=J+1) & (I<LongitudeR(l)<=I+1 & J<DepthsR(l)<=J+1))
             if (isempty(DepthsA(k))==0 & isempty(DepthsR(l))==1)
                 Zmoy(I,J)=min(DepthsA(k));
             elseif (isempty(DepthsA(k))==1 & isempty(DepthsR(l))==0)
                 Zmoy(I,J)=min(DepthsR(l));
             elseif (isempty(DepthsA(k))==1 & isempty(DepthsR(l))==1)
                 %Ne rien faire, i.e "Void"
             elseif (isempty(DepthsA(k))==0 & isempty(DepthsR(l))==0)
                 zAmin(I,J)=min(DepthsA(k));
                 DZ(I,J)=min(abs(zAmin(I,J)-DepthsR(l)));
                    if zAmin(I,J)<=DepthsR(l)
                        zRmin(I,J)=zAmin(I,J)+DZ(I,J);
                    else 
                        zRmin(I,J)=zAmin(I,J)-DZ(I,J);
                    end
                 Zmoy(I,J)=(zAmin(I,J)+zRmin(I,J))/2;
             end
         end
       Zm=-1*mean(Zmoy(I,J))
 end

Matlab response :"

Error using < Matrix dimensions must agree.

Error in plN_Tang (line 60) if ((I<LongitudeA(k)<=I+1 & J<DepthsA(k)<=J+1) & (I<LongitudeR(l)<=I+1 & J<DepthsR(l)<=J+1))"

What's wrong with the loop?

PS:I'd be so grateful if someone has an idea about this issue!