2022-04-07 10:34:03 -04:00

532 lines
14 KiB
Rust

#![allow(clippy::too_many_arguments)] // Clippy, shut
use crate::math_app::AppSettings;
use crate::misc::*;
use crate::parsing::{process_func_str, BackingFunction};
use crate::widgets::AutoComplete;
use eframe::{egui, epaint};
use egui::{
plot::{BarChart, PlotUi, Value},
widgets::plot::Bar,
};
use epaint::Color32;
use std::fmt::{self, Debug};
#[cfg(threading)]
use rayon::iter::ParallelIterator;
/// Represents the possible variations of Riemann Sums
#[derive(PartialEq, Debug, Copy, Clone)]
pub enum Riemann {
Left,
Middle,
Right,
}
impl fmt::Display for Riemann {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{:?}", self) }
}
lazy_static::lazy_static! {
/// Represents a "default" instance of `FunctionEntry`
pub static ref DEFAULT_FUNCTION_ENTRY: FunctionEntry = FunctionEntry::default();
}
/// `FunctionEntry` is a function that can calculate values, integrals,
/// derivatives, etc etc
#[derive(Clone)]
pub struct FunctionEntry {
/// The `BackingFunction` instance that is used to generate `f(x)`, `f'(x)`, and `f''(x)`
function: BackingFunction,
/// Stores a function string (that hasn't been processed via `process_func_str`) to display to the user
raw_func_str: String,
/// Minimum and Maximum values of what do display
min_x: f64,
max_x: f64,
/// If calculating/displayingintegrals are enabled
pub integral: bool,
/// If displaying derivatives are enabled (note, they are still calculated for other purposes)
pub derivative: bool,
back_data: Vec<Value>,
integral_data: Option<(Vec<Bar>, f64)>,
derivative_data: Vec<Value>,
extrema_data: Vec<Value>,
roots_data: Vec<Value>,
autocomplete: AutoComplete<'static>,
test_result: Option<String>,
}
impl Default for FunctionEntry {
/// Creates default FunctionEntry instance (which is empty)
fn default() -> FunctionEntry {
FunctionEntry {
function: BackingFunction::new(""),
raw_func_str: String::new(),
min_x: -1.0,
max_x: 1.0,
integral: false,
derivative: false,
back_data: Vec::new(),
integral_data: None,
derivative_data: Vec::new(),
extrema_data: Vec::new(),
roots_data: Vec::new(),
autocomplete: AutoComplete::default(),
test_result: None,
}
}
}
impl FunctionEntry {
/// Create autocomplete ui and handle user input
pub fn auto_complete(&mut self, ui: &mut egui::Ui, i: i32) -> (bool, bool, Option<String>) {
let (output_string, in_focus) = self.autocomplete.ui(ui, self.raw_func_str.clone(), i);
let changed = output_string != self.raw_func_str;
if changed {
self.update_string(&output_string);
}
(in_focus, changed, self.get_test_result())
}
/// Get function's cached test result
pub fn get_test_result(&self) -> Option<String> { self.test_result.clone() }
/// Update function string and test it
fn update_string(&mut self, raw_func_str: &str) {
let processed_func = process_func_str(raw_func_str);
let output = crate::parsing::test_func(&processed_func);
self.raw_func_str = raw_func_str.to_string();
if output.is_some() {
self.test_result = output;
return;
} else {
self.test_result = None;
}
self.function = BackingFunction::new(&processed_func);
self.invalidate_whole();
}
/// Get function that can be used to calculate integral based on Riemann Sum type
fn get_sum_func(&self, sum: Riemann) -> FunctionHelper {
match sum {
Riemann::Left => {
FunctionHelper::new(|left_x: f64, _: f64| -> f64 { self.function.get(left_x) })
}
Riemann::Right => {
FunctionHelper::new(|_: f64, right_x: f64| -> f64 { self.function.get(right_x) })
}
Riemann::Middle => FunctionHelper::new(|left_x: f64, right_x: f64| -> f64 {
(self.function.get(left_x) + self.function.get(right_x)) / 2.0
}),
}
}
/// Creates and does the math for creating all the rectangles under the graph
fn integral_rectangles(
&self, integral_min_x: &f64, integral_max_x: &f64, sum: &Riemann, integral_num: &usize,
) -> (Vec<(f64, f64)>, f64) {
if integral_min_x.is_nan() {
panic!("integral_min_x is NaN")
} else if integral_max_x.is_nan() {
panic!("integral_max_x is NaN")
}
let step = (integral_min_x - integral_max_x).abs() / (*integral_num as f64);
let sum_func = self.get_sum_func(*sum);
let data2: Vec<(f64, f64)> = dyn_iter(&step_helper(*integral_num, integral_min_x, &step))
.map(|x| {
let step_offset = step * x.signum(); // store the offset here so it doesn't have to be calculated multiple times
let x2: f64 = x + step_offset;
let (left_x, right_x) = match x.is_sign_positive() {
true => (*x, x2),
false => (x2, *x),
};
let y = sum_func.get(left_x, right_x);
(x + (step_offset / 2.0), y)
})
.filter(|(_, y)| !y.is_nan())
.collect();
let area = data2.iter().map(|(_, y)| y * step).sum();
(data2, area)
}
/// Helps with processing newton's method depending on level of derivative
fn newtons_method_helper(&self, threshold: &f64, derivative_level: usize) -> Vec<Value> {
let range = self.min_x..self.max_x;
let newtons_method_output: Vec<f64> = match derivative_level {
0 => newtons_method_helper(
threshold,
&range,
self.back_data.as_slice(),
&|x: f64| self.function.get(x),
&|x: f64| self.function.get_derivative_1(x),
),
1 => newtons_method_helper(
threshold,
&range,
self.derivative_data.as_slice(),
&|x: f64| self.function.get_derivative_1(x),
&|x: f64| self.function.get_derivative_2(x),
),
_ => unreachable!(),
};
dyn_iter(&newtons_method_output)
.map(|x| Value::new(*x, self.function.get(*x)))
.collect()
}
/// Does the calculations and stores results in `self`
pub fn calculate(
&mut self, min_x: &f64, max_x: &f64, width_changed: bool, settings: &AppSettings,
) {
if self.test_result.is_some() {
return;
}
let resolution: f64 = settings.plot_width as f64 / (max_x.abs() + min_x.abs());
let resolution_iter = resolution_helper(&settings.plot_width + 1, min_x, &resolution);
// Makes sure proper arguments are passed when integral is enabled
if self.integral && settings.integral_changed {
self.invalidate_integral();
}
let mut partial_regen = false;
let min_max_changed = (min_x != &self.min_x) | (max_x != &self.max_x);
let derivative_required = settings.do_extrema | self.derivative;
self.min_x = *min_x;
self.max_x = *max_x;
if width_changed {
self.invalidate_back();
self.invalidate_derivative();
} else if min_max_changed && !self.back_data.is_empty() {
partial_regen = true;
let x_data: SteppedVector = self
.back_data
.iter()
.map(|ele| ele.x)
.collect::<Vec<f64>>()
.into();
let back_data: Vec<Value> = dyn_iter(&resolution_iter)
.map(|x| {
if let Some(i) = x_data.get_index(x) {
self.back_data[i]
} else {
Value::new(*x, self.function.get(*x))
}
})
.collect();
debug_assert_eq!(back_data.len(), settings.plot_width + 1);
self.back_data = back_data;
if derivative_required {
let new_derivative_data: Vec<Value> = dyn_iter(&resolution_iter)
.map(|x| {
if let Some(i) = x_data.get_index(x) {
self.derivative_data[i]
} else {
Value::new(*x, self.function.get_derivative_1(*x))
}
})
.collect();
debug_assert_eq!(new_derivative_data.len(), settings.plot_width + 1);
self.derivative_data = new_derivative_data;
} else {
self.invalidate_derivative();
}
} else {
self.invalidate_back();
self.invalidate_derivative();
}
let threshold: f64 = resolution / 2.0;
if !partial_regen {
if self.back_data.is_empty() {
let data: Vec<Value> = dyn_iter(&resolution_iter)
.map(|x| Value::new(*x, self.function.get(*x)))
.collect();
debug_assert_eq!(data.len(), settings.plot_width + 1);
self.back_data = data;
}
if derivative_required && self.derivative_data.is_empty() {
let data: Vec<Value> = dyn_iter(&resolution_iter)
.map(|x| Value::new(*x, self.function.get_derivative_1(*x)))
.collect();
debug_assert_eq!(data.len(), settings.plot_width + 1);
self.derivative_data = data;
}
}
if self.integral {
if self.integral_data.is_none() {
let (data, area) = self.integral_rectangles(
&settings.integral_min_x,
&settings.integral_max_x,
&settings.riemann_sum,
&settings.integral_num,
);
self.integral_data =
Some((data.iter().map(|(x, y)| Bar::new(*x, *y)).collect(), area));
}
} else {
self.invalidate_integral();
}
// Calculates extrema
if settings.do_extrema && (min_max_changed | self.extrema_data.is_empty()) {
self.extrema_data = self.newtons_method_helper(&threshold, 1);
}
// Calculates roots
if settings.do_roots && (min_max_changed | self.roots_data.is_empty()) {
self.roots_data = self.newtons_method_helper(&threshold, 0);
}
}
/// Displays the function's output on PlotUI `plot_ui` with settings `settings`.
/// Returns an `Option<f64>` of the calculated integral.
pub fn display(
&self, plot_ui: &mut PlotUi, settings: &AppSettings, main_plot_color: Color32,
) -> Option<f64> {
if self.test_result.is_some() {
return None;
}
let derivative_str = self.function.get_derivative_str();
let step = (settings.integral_min_x - settings.integral_max_x).abs()
/ (settings.integral_num as f64);
// Plot back data
if !self.back_data.is_empty() {
plot_ui.line(
self.back_data
.to_line()
.color(main_plot_color)
.name(&self.raw_func_str),
);
}
// Plot derivative data
if self.derivative && !self.derivative_data.is_empty() {
plot_ui.line(
self.derivative_data
.to_line()
.color(Color32::GREEN)
.name(derivative_str),
);
}
// Plot extrema points
if settings.do_extrema {
plot_ui.points(
self.extrema_data
.to_points()
.color(Color32::YELLOW)
.name("Extrema")
.radius(5.0), // Radius of points of Extrema
);
}
// Plot roots points
if settings.do_roots {
plot_ui.points(
self.roots_data
.to_points()
.color(Color32::LIGHT_BLUE)
.name("Root")
.radius(5.0), // Radius of points of Roots
);
}
// Plot integral data
match &self.integral_data {
Some(integral_data) => {
plot_ui.bar_chart(
BarChart::new(integral_data.0.clone())
.color(Color32::BLUE)
.width(step),
);
// return value rounded to 8 decimal places
Some(crate::misc::decimal_round(integral_data.1, 8))
}
_ => None,
}
}
/// Invalidate entire cache
pub fn invalidate_whole(&mut self) {
self.invalidate_back();
self.invalidate_integral();
self.invalidate_derivative();
self.extrema_data.clear();
self.roots_data.clear();
}
/// Invalidate `back` data
pub fn invalidate_back(&mut self) { self.back_data.clear(); }
/// Invalidate Integral data
pub fn invalidate_integral(&mut self) { self.integral_data = None; }
/// Invalidate Derivative data
pub fn invalidate_derivative(&mut self) { self.derivative_data.clear(); }
/// Runs asserts to make sure everything is the expected value
#[cfg(test)]
pub fn tests(
&mut self, settings: AppSettings, back_target: Vec<(f64, f64)>,
derivative_target: Vec<(f64, f64)>, area_target: f64, min_x: f64, max_x: f64,
) {
{
self.calculate(&min_x, &max_x, true, &settings);
let back_target = back_target;
assert!(!self.back_data.is_empty());
assert_eq!(self.back_data.len(), settings.plot_width + 1);
let back_vec_tuple = self.back_data.to_tuple();
assert_eq!(back_vec_tuple, back_target);
assert!(self.integral);
assert!(self.derivative);
assert_eq!(!self.roots_data.is_empty(), settings.do_roots);
assert_eq!(!self.extrema_data.is_empty(), settings.do_extrema);
assert!(!self.derivative_data.is_empty());
assert!(self.integral_data.is_some());
assert_eq!(self.derivative_data.to_tuple(), derivative_target);
assert_eq!(self.integral_data.clone().unwrap().1, area_target);
}
{
self.update_string("sin(x)");
assert!(self.get_test_result().is_none());
assert_eq!(&self.raw_func_str, "sin(x)");
self.integral = false;
self.derivative = false;
assert!(!self.integral);
assert!(!self.derivative);
assert!(self.back_data.is_empty());
assert!(self.integral_data.is_none());
assert!(self.roots_data.is_empty());
assert!(self.extrema_data.is_empty());
assert!(self.derivative_data.is_empty());
self.calculate(&min_x, &max_x, true, &settings);
assert!(!self.back_data.is_empty());
assert!(self.integral_data.is_none());
assert!(self.roots_data.is_empty());
assert!(self.extrema_data.is_empty());
assert!(self.derivative_data.is_empty());
}
}
}
#[cfg(test)]
mod tests {
use super::*;
fn app_settings_constructor(
sum: Riemann, integral_min_x: f64, integral_max_x: f64, pixel_width: usize,
integral_num: usize,
) -> AppSettings {
crate::math_app::AppSettings {
riemann_sum: sum,
integral_min_x,
integral_max_x,
integral_changed: true,
integral_num,
do_extrema: false,
do_roots: false,
plot_width: pixel_width,
}
}
static BACK_TARGET: [(f64, f64); 11] = [
(-1.0, 1.0),
(-0.8, 0.6400000000000001),
(-0.6, 0.36),
(-0.4, 0.16000000000000003),
(-0.19999999999999996, 0.03999999999999998),
(0.0, 0.0),
(0.19999999999999996, 0.03999999999999998),
(0.3999999999999999, 0.15999999999999992),
(0.6000000000000001, 0.3600000000000001),
(0.8, 0.6400000000000001),
(1.0, 1.0),
];
static DERIVATIVE_TARGET: [(f64, f64); 11] = [
(-1.0, -2.0),
(-0.8, -1.6),
(-0.6, -1.2),
(-0.4, -0.8),
(-0.19999999999999996, -0.3999999999999999),
(0.0, 0.0),
(0.19999999999999996, 0.3999999999999999),
(0.3999999999999999, 0.7999999999999998),
(0.6000000000000001, 1.2000000000000002),
(0.8, 1.6),
(1.0, 2.0),
];
fn do_test(sum: Riemann, area_target: f64) {
let settings = app_settings_constructor(sum, -1.0, 1.0, 10, 10);
let mut function = FunctionEntry::default();
function.update_string("x^2");
function.integral = true;
function.derivative = true;
function.tests(
settings,
BACK_TARGET.to_vec(),
DERIVATIVE_TARGET.to_vec(),
area_target,
-1.0,
1.0,
);
}
#[test]
fn function_entry_test() {
do_test(Riemann::Left, 0.9600000000000001);
do_test(Riemann::Middle, 0.92);
do_test(Riemann::Right, 0.8800000000000001);
}
}