codethrasher

I have very fuzzy memories of playing games like Tank Wars when I was a kid.

I’ve always been interested in simulations.

I’m reposting this.

Tags Search tags: SPC n m or SPC o a m Add tag: SPC m q Links Insert link: SPC m l l File links have the structure [[file:relative_link_to_file][some_title]] To link to a specific heading in a file [[file:relative_link::header title][some_title]] header t…

1 2 3 4 5 6 7 curl -0 -v -X POST https://some.api.com/graphql \ -H 'Content-Type: application/json' \ -d @- << EOF { "query": "query { someQuery (someArg: false) { name } }" } EOF curl will probably complain about the -X POST being inferred, but it sho…

Take a function like below… 1 2 3 4 5 6 7 8 type Combinable = string | number function add(a: Combinable, b: Combinable): Combinable { if (typeof a === 'string' || typeof b === 'string') { return a.toString() + b.toString() } return a + b } If we w…

1 2 // say you have some var hangin' around called `name` let x: string = name ??

In TS@4 a type can reference itself, e.g. 1 2 3 4 5 6 7 8 9 type JSONValue = | string | number | boolean | null | JSONValue[] | { [k: string]: JSONValue } Previously, this would not be possible without some messy hacks.

1 type Address = [number, string, string, number] Say you now have a function printAddress which takes an Address type as its arg. 1 2 3 function printAddress(...address: Address) { // ...stuff } Your editor (before TS@4) would hint that the arguments

1 type Foo<T extends any[]> = [boolean, ...T, boolean] Before TS@4.0 ...T would need to be the last element, but now we can spread the T type nested between known types; e.g.

TypeScript has a way of describing a build process as multiple subpieces of a project.

Out of the box, Jest mostly works in a Monorepo environment, with the exception of a few Babel plugins so that (as an example) TypeScript works.

“colocation” is a pattern wherein you keep the query/mutation as close to the consuming component as possible.

package.json resolutions field yarn specific Allows you to force the use of a particular version for a nested dependency. e.g.: 1 2 3 4 "devDependencies": { "@angular/cli": "1.0.3", "typescript": "2.3.2" } yarn.lock will contain: 1 2 3 4 5 6 7 "types…

A cipher is defined over the spaces of: All Keys, \(\mathscr{K}\) All Messages, \(\mathscr{M}\) All Cipher texts, \(\mathscr{C}\) Cipher (defined as a triple, \((\mathscr{K}, \mathscr{M}, \mathscr{C})\)) as a pair of algorithms \((\mathbf{E}, \mathbf{D})\)

A vector with non-negative components (representing specific probabilities) which add up to one e.g.

\begin{equation} x \in U:P(x) = \frac{1}{|U|} \end{equation} Where \(|U|\) is the size of the universe (set).

x0: P(x) = 1,∀ x ≠ x0: P(x) = 0 In Probability Theory, a point distribution is a distribution which assigns all the probability to a given point (set element).

Digital Signature

A function of the content being “signed”

The measurement of accuracy of a hypothesis function.

Gradient Descent Cost Function Hypothesis Function Artificial Neural Network

An optimization algorithm for finding the local minimum of a differentiable function.

A function which maps values \(x\) to an output value \(y\).

Artificial Neural Network (ANN) Layers All learning occurs in the layers.

A linear mapping from a vector space to a field of scalars.

Tensors Tensor Product

Bases Bases Transformation Coordinate Transformation Covectors Dual Space Identity Matrix Invertible Matrix Invertible Matrix Orthonormal Basis Tensor Product Tensors Vector Space Axioms (Vector Space)

A mapping from \(\mathbf{V} \rightarrow \mathbf{W}\) that preserves the operations of addition and scalar multiplication.

A function of several variables that is linear, separately, in each variable.

The space of all linear functionals \(f:V\rightarrow \mathbb{R}\), noted as \(V^{*}\) The dual space has the same dimension as the corresponding vector space or, given a space \(V\), with bases \((v_{1},…,v_{n})\), there exists a dual space \(V^{*}\) with…

The space of all linear functionals \(f:V\rightarrow \mathbb{R}\), noted as \(V^{*}\) The dual space has the same dimension as the corresponding vector space or, given a space \(V\), with bases \((v_{1},…,v_{n})\), there exists a dual space \(V^{*}\) with…

The bubble, created by the Sun’s plasma (see Solar Wind), which encompasses the Sun itself.

TODO

As a linear representation A tensor can be represented as a vector of x-number of dimensions.

\begin{equation} \delta_{ij}= \begin{cases} 0 & \text{if i \(\neq\) j}\\\ 1 & \text{if i \(=\) j} \end{cases} \end{equation}

a basis for an n-dimensional vector space \(V\) is any ordered set of linearly independent vectors \((\mathbf{e}_{1}, \mathbf{e}_{2},…,\mathbf{e}_{n})\) An arbitrary vector \(\mathbf{x}\) in \(V\) can be expressed as a linear combination of the basis vect…

An orthonormal basis is a basis where all the vectors are one unit long and all perpendicular to each other (e.g. the Cartesian plane)

Consider two bases \((\mathbf{e}_{1},\mathbf{e}_{2})\) and \((\mathbf{\tilde{e}}_{1},\mathbf{\tilde{e}}_{2})\), where we consider the former the old basis and the latter the new basis.

\begin{equation} \mathbf{I}(\mathbf{X})=\mathbf{X} \end{equation} Where any \(nxn\) matrix is established via the Kronecker Delta, e.g.

A matrix, which when multiplied by another matrix, results in the identity matrix.

also known as a linear space A collection of objects known as “vectors”.

To qualify as a vector space, a set \(V\) and its associated operations of addition (\(+\)) and multiplication/scaling (\(\cdot\)) must adhere to the below: Associativity \begin{equation} \mathbf{u}+(\mathbf{v}+\mathbf{w}) = (\mathbf{u} + \mathbf{v}) + \m…

An property (of a mathematical object) is invariant if, after some operation(s) are applied, that property remains unchanged.

The Inflationary Universe Standard Model Cosmic Inflation Cosmological Constant Cosmic Microwave Background

source The Inflationary Universe: A Possible Solution To The Horizon And Flatness Problems (Guth, 1980) Questions I still have DONE WHY#1: why is that approximation unstable?

This refers to the Cosmological “Standard Model”, i.e. the \(\Lambda\)CDM.