array of structs. 
% Each layer is one struct.
% The first layer must be of 'type' input and the last layer must be of
% type 'loss'
% Each layer has fields 'inInd' and 'outInd'. These are indices to where
% the input of the layer comes from and where the output of the layer goes
% to.
lenet = { ...
    struct('type','input','inInd',0,'outInd',1,'blobSize',[28 28 1 100],'fName',trainImages,'scale',1/256,'dataType','uint8'), ...
    struct('type','input','inInd',0,'outInd',2,'blobSize',[10 100],'fName',train