The frame is likely made of wood or metal, because most picture frames are made of these materials.

It's important to note that array numbering in Julia starts with 1, not with 0 as in most other languages.

the following dataset

You do not need to include any additional packages for it.

Basic linear algebra features are already integrated into the Julia standard library.

because of it simplicity

iterator

: When indexing into a dataset(), what happens in the background is a call to .getitem(i)

.getitem = function(i) { list(x = self$x[i, ], y = self$y[i]) },

items

consisting of one input

For example, for sentiment classification tokens awesome, brilliant, great will have higher probability given positive class then negative. Similarly, tokens awful, boring, bad will have higher probability given negative class then positive.

aka Add-1 smoothing

prior probability P(y=k): class probability before looking at data (i.e., before knowing x);

The hypothesis is that your brain searched for other words that can be used in the same contexts, found some (e.g., wine), and made a conclusion that tezgüino has meaning similar to those other words. This is the distributional hypothesis:

But how do we know what is meaning?

Functions should take the data structures that users have as opposed to the data structure that developers want. For example, a model function’s only interface should not be constrained to matrices. Frequently, users will have non-numeric predictors such as factors.

In the context of modeling, it is also important to avoid highly technical jargon, such as Greek letters or obscure terms in terms.

Медицина: врачи могут использовать бота для получения ответов на медицинские вопросы и улучшения качества диагностики и лечения.

Note that parsnip constrains the outcome column of a classification model to be encoded as a factor; using binary numeric values will result in an error.

Some of the original argument names can be fairly jargon-y. For example, to specify the amount of regularization to use in a glmnet model, the Greek letter lambda is used. While this mathematical notation is commonly used in the statistics literature, it is not obvious to many people what lambda represents (especially those who consume the model results).

For other types of models, the interfaces may be even more disparate. For a person trying to do data analysis, these differences require the memorization of each package’s syntax and can be very frustrating.

The parsnip package, one of the R packages that are part of the tidymodels metapackage, provides a fluent and standardized interface for a variety of different models. In this chapter, we give some motivation for why a common interface is beneficial for understanding and building models in practice and show how to use the parsnip package.

This begs the question: “How can we tell what is best if we don’t measure performance until the test set?”

These results can be “stacked” and added to a ggplot(), as shown in Figure 3.3.

As an example, M. Kuhn and Johnson (2020) use data to model the daily ridership of Chicago’s public train system using predictors such as the date, the previous ridership results, the weather, and other factors. Table 1.1 shows an approximation of these authors’ hypothetical inner monologue when analyzing these data and eventually selecting a model with sufficient performance.

Chapter 4, “Subsetting”, now distinguishes between [ and [[ by their intention: [ extracts many values and [[ extracts a single value (previously they were characterised by whether they “simplified” or “preserved”).

Without calculus and the ideas of functions and their derivatives, Smith was not able to think about prices in a modern way where price is shaped by demand and supply. Instead, for Smith, each item has a “natural price”: a fixed quantity that depends on the amount of labor used to produce the item. Nowadays, we understand that productivity changes as new methods of production and new inventions are introduced.

“people” / “passengers” / “customers” / “patients” / “cases” / “passenger deaths”: these are different different ways to refer to people. we will consider such quantities to have dimension P, for population.

There are other dimensions: volume, force, pressure, energy, torque, velocity, acceleration, and such. These are called compound dimensions because we represent them as combinations of the fundamental dimensions, L, T, and M. The notation for these combinations involves multiplication and division.

Another clue is whether “zero” means “nothing.” Daily temperatures in the winter are often near “zero” on the Fahrenheit or Celcius scales, but that in no way means there is a complete absence of heat. Those scales are arbitrary. Another way to think about this clue is whether negative values are meaningful. If so, thinking in terms of orders of magnitude is not likely to be useful.