Hi! I’m new to gretl programming. Please, can anyone tell me why my code doesn’t recognize my double loop. I don’t understand. # a 14 de mayo de 2016 # función que genera la contribución de Shapley include drop_majo.inp include R2_majo.inp function matrix shapley(matrix X "Variables explicativas", matrix y "Variable dependiente") scalar T=rows(X) #número de observaciones scalar N=cols(X) #número de variables explicativas scalar M=2^N #número de regresiones factibles scalar M2=M-1 scalar N2=N-1 matrix Z = zeros(M,1) matrix C = zeros(1,N) loop k=0..M2 matrix Xs=X loop for (i=N; i=1;i-=1) if floor((k%(2^i))/2^(i-1))==0 matrix Xs=dropcol(Xs,i) endif endloop matrix Z[k+1]=R2(Xs,y) endloop print Z loop j=1..N loop m=0..M2 if floor(m%(2^j)/2^(j-1))==0 matrix C[j]=C[j]+Z[m+1] else matrix C[j]=C[j]-Z[m+1] endif endloop matrix C[j]=C[j]/(2^(N-1)) endloop print C end Also, sometimes the console freezes. It doesn’t respond to anything I write, so I have to constantly close Gretl. Thanks! María José Enviado desde Correo para Windows 10