## Why is an activation function notated as "g"?

3

In many cases an activation function is notated as g (e.g. Andrew Ng's Course courses), especially if it doesn't refer to any specific activation function such as sigmoid.

However, where does this convention come from? And for what reason did g start to be used?

1It’s just a notation. You can call it whatever you want. a BC d – Vivek Khetan – 2017-11-03T12:25:43.860

Yes but what is the reason? That is the point of my question. – Blaszard – 2017-11-03T13:12:27.800

Read some linear algebra. – Vivek Khetan – 2017-11-03T13:30:26.333

2That is not an answer. – Blaszard – 2017-11-06T10:03:58.923

ESL uses $\sigma(.)$. This is a dumb question. – generic_user – 2017-11-06T21:37:34.047

@generic_user What is ESL? – Blaszard – 2017-11-13T22:37:17.757

– generic_user – 2017-11-13T23:00:38.040

"Read some linear algebra", "ESL uses $\sigma$"... Those are dumb responses. I do agree that maybe the question could be more like: "What is the standard letter for the activation function and why?" And then talk about examples like ESL uses sigma and Andrew ng uses g, etc. Because not everyone uses g for the activation function. – Agustin Barrachina – 2020-04-13T13:03:54.157