I have to define polynomials ARX model orders [na nb nc], for a set of four inputs and one output as the need to use the tool NNSYSID Toolbox, the data are as follows:
z8=iddata(y1,[u1 u2 u3 u4],1);
Data set with 1 output and 4 inputs. The number of data points is 587. The inputs are
delayest using the command I get the following error
Error using delayest (line 87) The combination of delay limits will result in 2560000 delay-combinations, which is more than the allowed number of tests (10000). Either make the delay span more narrow or increase maximum allowable tests using the sixth input argument of the "delayest" command.