diff --git a/matlab/tfgm/tf_tools/error_operator_norm.m b/matlab/tfgm/tf_tools/error_operator_norm.m
deleted file mode 100644
index cdfe4651a2c68663eeef531c242a65779473ba25..0000000000000000000000000000000000000000
--- a/matlab/tfgm/tf_tools/error_operator_norm.m
+++ /dev/null
@@ -1,18 +0,0 @@
-function eig_val = error_operator_norm(gab_mul, svd_res)
-% compute error M -UDU.T
-
-u_mat = svd_res.U;
-s =  svd_res.D;
-u_h = u_mat';
-
-u_op = @(x) u_mat*x;
-s_op = @(x) s*x;
-u_h_op = @(x)u_h*x;
-
-a_est = @(x) real(u_op(s_op(u_h_op(x))));
-
-err_op = @(x) gab_mul(x) - a_est(x) ;
-
-eig_val = abs(eigs(err_op, size(u_mat,1),1));
-
-end
\ No newline at end of file