What it means
The seventh Greek letter. η is the learning rate in machine learning, efficiency in engineering and, in many books, viscosity.
Read aloud in real formulas
θ ← θ − η ∇L(θ)
Aethel says
theta is updated to theta minus eta times the gradient of L of theta
η sets the size of each step
η = 1 − T_c / T_h
Aethel says
eta equals 1 minus T sub c over T sub h
the efficiency of a Carnot engine
Typing it
- LaTeX
- \eta (capital: H)
- Unicode
- U+03B7, U+0397
Formulas that use it
Questions
How do you pronounce eta (η)?
It is said “eta”, roughly AY-tuh (US), EE-tuh (UK).
What does η mean in maths?
The seventh Greek letter. η is the learning rate in machine learning, efficiency in engineering and, in many books, viscosity.
How do you type η?
In LaTeX, write \eta (capital: H). Its Unicode code point is U+03B7, U+0397.
What is η often confused with?
It is easy to mistake for n, which it resembles in handwriting.