Regarding implementation of neural network through equations

Dear sir,

I am trying to find out output of trained neural network in two ways ...one through equations which are equivalent to implemented neural network (with weights and biases) and one through simulation of neural network. Outputs from both the methods I am getting are not same. So I want to know why is it so and how to make both same? plz let me know ur view. Thanks

In below code y2 and Ya are not getting same and mse of ya with target is larger than y2 with target.

yn = B2 + LW22 * logsig( B1 + LW11 * xn )

ya = mapminmax.reverse(yn,tsettings) % output from equations of NN

y2=net(x) % output from simulated NN

mse1=mse(ya,t)

mse2=mse(y2,t)