## transfer function purelin equation based on neural network toolbox

### Arrya Anandika (view profile)

on 10 Apr 2019
Latest activity Edited by Greg Heath

### Greg Heath (view profile)

on 13 Apr 2019
what is equation of pureline based on neural network toolbox? as i have read before, that purelin transfer function is a = purelin(n) = n. but from simulation in neural network toolbox get different result from the equation. is the equation wrong?
thank you.

Brendan Hamm

### Brendan Hamm (view profile)

on 11 Apr 2019
Your equation is correct, but in a neural network, n will be a linear combination of the inputs from the prior nodes multiplied by their weights and added to the bias.
So in effect purelin is just allowing this linear equation to pass to the next layer directly as opposed to applying another transfer function.
Arrya Anandika

### Arrya Anandika (view profile)

on 11 Apr 2019
yeah, i have done it. but when i compare matlab simulation with calculate equation, i don't get same result. what's wrong?
Greg Heath

### Greg Heath (view profile)

on 13 Apr 2019
How are we supposed to know what you did wrong if you don't demonstrate it???
Greg

on 11 Apr 2019

help purelin
doc purelin
Greg

Brendan Hamm

### Brendan Hamm (view profile)

on 12 Apr 2019
The input layer will include a mapminmax transformation, which maps the minimum value of each input to -1 and the maximum value to +1.
Arrya Anandika

### Arrya Anandika (view profile)

on 13 Apr 2019
so, we must set input range -1 to 1 sir?
with normalization?
because, based example that i have tried, the target that i want is 0 or 1, but in equation, i got the result many variation, like 2, 3, even 23491.
i don't know what's wrong.
Greg Heath

### Greg Heath (view profile)

on 13 Apr 2019
1. Now and in the future,
SHOW EXACTLY WHAT YOU DID IN ADDITION IN YOUR ATTEMPT TO EXPLAIN IT!
2. Have you read the documentation and tried the examples?
Greg