The Modern Mathematics of Deep Learningexplained for non-mathematicians

A probability density estimate

Penguin learning project

The project uses 342 complete Palmer penguin records: 240 training-pool and 102 held-out rows. The selected training rows determine feature scaling and model parameters. Source CSV

This project trains weights with softmax, unlike the homepage lab, which uses nearest species averages. Same penguin measurements; different classification methods. Predictions can differ.

Probability and expectation · Describe random variables and their averages under a law.

Project vectors have two features; the training matrix has n rows and two columns. Mathematical tools may operate on these values when their assumptions apply.

Consider this concept alongside the project; its source assumptions may differ. These observations do not prove a theorem.

Input: 12 × 2; Held-out evaluation: 102 · #58 · 40.6 mm, 193 mm. Known answer: Adélie; Prediction: Adélie · [≈0.7383, ≈0.2444, ≈0.01737].

Used in these source sections: 1.2 Learning from examples

A density fₛ assigns nonnegative values to data z and integrates to one with respect to a reference measure.

A fitted density describes how probability is distributed over possible data.

Source formula example

Z{\mathcal{Z}}

illustration · This uses counting measure on two points; continuous densities need integration rather than summation.

Symbols

𝒵𝒵
The data space.
zz
A data value.
fsf_{s}
A density fitted using sample s.
μμ
A reference measure.

Source formula example

This source example uses its own inputs and assumptions. Editing it does not change the project.

Edit a value or the code, then run the example. This is a finite demonstration, not a proof of the paper’s theorem.

This example’s data flow

Initial values in code

  • Z = [0, 1]
  • density = [0.25, 0.75]
  • z = 1

Calculated here

Result expression: { Z, density, z, densityAtZ: density[Z.indexOf(z)], total: density.reduce((a, b) => a + b, 0), }

Returns

Example result
Z
array (2 items): [0, 1]
density
array (2 items): [0.25, 0.75]
z
1
densityAtZ
0.75
total
1

Read numbers from input and return the result. JavaScript basics.

Result

Enable JavaScript to run this example.

Technical statement

The numerical values are invented. This uses counting measure on two points; continuous densities need integration rather than summation.

Source: Inline notation