Fireside Chats
Last edited: August 8, 2025Fireside Chats are a group of broadcasts by Franklin D. Roosevelt (FDR) which allowed him to speak directly to the people.
Fireside Index
Last edited: August 8, 2025Below you will find a list of the Fireside articles.
Article | Date |
---|---|
Welcome to the Fireside | |
Make Models Go Brrr | |
Todo Lists | |
“Let’s find time” | |
Pipes are so bad |
First Order ODEs
Last edited: August 8, 2025First Order ODEs are Differential Equations that only takes one derivative.
Typically, by the nature of how they are modeled, we usually state it in a equation between three things:
\begin{equation} t, y(t), y’(t) \end{equation}
as in—we only take one derivative.
Sometimes the solution may not be analytic, but is well-defined:
\begin{equation} y’ = e^{-x^{2}} \end{equation}
we know that, by the fundamental theorem of calculus, gives us:
\begin{equation} y(x) = \int_{0}^{x} e^{-s{2}} \dd{s} \end{equation}
First-Order Linear Systems of ODEs
Last edited: August 8, 2025Consider the case where there are two functions interacting with each other:
\begin{equation} y_1(t) \dots y_{2}(t) \end{equation}
So we have more than one dependent function, with functions \(y_1, y_1’, y_2, y_2’\) and so forth. To deal with this, we simply make it into a matrix system:
\begin{equation} y(t) = \mqty(y_1(t) \\ \dots \\ y_{n}(t)) \end{equation}
For instance, should we have:
\begin{equation} \begin{cases} y_1’ = 3y_1 - 2y_2 \\ y_2’ = -y_1 + 5y_2 \end{cases} \end{equation}
fixed-point iteration
Last edited: August 8, 2025Fixed point iteration is a method for finding a fixed point of a function, which is a value that remains unchanged when the function is applied to it (i.e., f(x) = x). The method works by repeatedly applying the function to an initial guess:
- Start with an initial approximation x₀
- Compute successive iterations: xₙ₊₁ = f(xₙ)
- Continue until convergence (|xₙ₊₁ - xₙ| < ε) or maximum iterations
The method converges if the function is a contraction mapping in the neighborhood of the fixed point (|f’(x)| < 1).