2022-03-10 10:15:52 -05:00

583 lines
14 KiB
Rust

#![allow(clippy::too_many_arguments)] // Clippy, shut
use crate::function_output::FunctionOutput;
#[allow(unused_imports)]
use crate::misc::{debug_log, SteppedVector};
use crate::egui_app::{DEFAULT_FUNCION, DEFAULT_RIEMANN};
use crate::parsing::BackingFunction;
use eframe::egui::plot::PlotUi;
use eframe::egui::{plot::Value, widgets::plot::Bar};
use std::fmt::{self, Debug};
#[derive(PartialEq, Debug, Copy, Clone)]
pub enum RiemannSum {
Left,
Middle,
Right,
}
impl fmt::Display for RiemannSum {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{:?}", self) }
}
lazy_static::lazy_static! {
pub static ref EMPTY_FUNCTION_ENTRY: FunctionEntry = FunctionEntry::empty();
}
#[derive(Clone)]
pub struct FunctionEntry {
function: BackingFunction,
func_str: String,
min_x: f64,
max_x: f64,
pixel_width: usize,
output: FunctionOutput,
pub(crate) integral: bool,
pub(crate) derivative: bool,
integral_min_x: f64,
integral_max_x: f64,
integral_num: usize,
sum: RiemannSum,
roots: bool,
extrema: bool,
}
impl FunctionEntry {
// Creates Empty Function instance
pub fn empty() -> Self {
Self {
function: BackingFunction::new(DEFAULT_FUNCION),
func_str: String::new(),
min_x: -1.0,
max_x: 1.0,
pixel_width: 100,
output: FunctionOutput::new_empty(),
integral: false,
derivative: false,
integral_min_x: f64::NAN,
integral_max_x: f64::NAN,
integral_num: 0,
sum: DEFAULT_RIEMANN,
roots: true,
extrema: true,
}
}
pub fn update(
&mut self, func_str: String, integral: bool, derivative: bool, integral_min_x: Option<f64>,
integral_max_x: Option<f64>, integral_num: Option<usize>, sum: Option<RiemannSum>,
extrema: bool, roots: bool,
) {
// If the function string changes, just wipe and restart from scratch
if func_str != self.func_str {
self.func_str = func_str.clone();
self.function = BackingFunction::new(&func_str);
self.output.invalidate_whole();
}
self.derivative = derivative;
self.integral = integral;
self.extrema = extrema;
self.roots = roots;
// Makes sure proper arguments are passed when integral is enabled
if integral
&& (integral_min_x != Some(self.integral_min_x))
| (integral_max_x != Some(self.integral_max_x))
| (integral_num != Some(self.integral_num))
| (sum != Some(self.sum))
{
self.output.invalidate_integral();
self.integral_min_x = integral_min_x.expect("integral_min_x is None");
self.integral_max_x = integral_max_x.expect("integral_max_x is None");
self.integral_num = integral_num.expect("integral_num is None");
self.sum = sum.expect("sum is None");
}
}
pub fn run_back(&mut self) -> (Vec<Value>, Option<(Vec<Bar>, f64)>, Option<Vec<Value>>) {
let resolution: f64 = (self.pixel_width as f64 / (self.max_x - self.min_x).abs()) as f64;
let back_values: Vec<Value> = {
if self.output.back.is_none() {
self.output.back = Some(
(0..self.pixel_width)
.map(|x| (x as f64 / resolution as f64) + self.min_x)
.map(|x| Value::new(x, self.function.get(x)))
.collect(),
);
}
self.output.back.as_ref().unwrap().clone()
};
let derivative_values: Option<Vec<Value>> = {
if self.output.derivative.is_none() {
self.output.derivative = Some(
(0..self.pixel_width)
.map(|x| (x as f64 / resolution as f64) + self.min_x)
.map(|x| Value::new(x, self.function.get_derivative_1(x)))
.collect(),
);
}
Some(self.output.derivative.as_ref().unwrap().clone())
};
let integral_data = match self.integral {
true => {
if self.output.integral.is_none() {
let (data, area) = self.integral_rectangles();
self.output.integral =
Some((data.iter().map(|(x, y)| Bar::new(*x, *y)).collect(), area));
}
let cache = self.output.integral.as_ref().unwrap();
Some((cache.0.clone(), cache.1))
}
false => None,
};
(back_values, integral_data, derivative_values)
}
// Creates and does the math for creating all the rectangles under the graph
fn integral_rectangles(&self) -> (Vec<(f64, f64)>, f64) {
if self.integral_min_x.is_nan() {
panic!("integral_min_x is NaN")
} else if self.integral_max_x.is_nan() {
panic!("integral_max_x is NaN")
}
let step = (self.integral_min_x - self.integral_max_x).abs() / (self.integral_num as f64);
let mut area: f64 = 0.0;
let data2: Vec<(f64, f64)> = (0..self.integral_num)
.map(|e| {
let x: f64 = ((e as f64) * step) + self.integral_min_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 = match self.sum {
RiemannSum::Left => self.function.get(left_x),
RiemannSum::Right => self.function.get(right_x),
RiemannSum::Middle => {
(self.function.get(left_x) + self.function.get(right_x)) / 2.0
}
};
if !y.is_nan() {
area += y * step;
}
(x + (step_offset / 2.0), y)
})
.filter(|(_, y)| !y.is_nan())
.collect();
// assert_eq!(data2.len(), self.integral_num);
(data2, area)
}
pub fn get_func_str(&self) -> &str { &self.func_str }
// Updates riemann value and invalidates integral_cache if needed
pub fn update_riemann(mut self, riemann: RiemannSum) -> Self {
if self.sum != riemann {
self.sum = riemann;
self.output.invalidate_integral();
}
self
}
// Toggles integral
pub fn integral(mut self, integral: bool) -> Self {
self.integral = integral;
self
}
#[allow(dead_code)]
pub fn integral_num(mut self, integral_num: usize) -> Self {
self.integral_num = integral_num;
self
}
#[allow(dead_code)]
pub fn pixel_width(mut self, pixel_width: usize) -> Self {
self.pixel_width = pixel_width;
self
}
#[allow(dead_code)]
pub fn integral_bounds(mut self, min_x: f64, max_x: f64) -> Self {
if min_x >= max_x {
panic!("integral_bounds: min_x is larger than max_x");
}
self.integral_min_x = min_x;
self.integral_max_x = max_x;
self
}
// Finds roots
fn roots(&mut self) {
let resolution: f64 = (self.pixel_width as f64 / (self.max_x - self.min_x).abs()) as f64;
let mut root_list: Vec<Value> = Vec::new();
let mut last_ele: Option<Value> = None;
for ele in self.output.back.as_ref().unwrap().iter() {
if last_ele.is_none() {
last_ele = Some(*ele);
continue;
}
let last_ele_signum = last_ele.unwrap().y.signum();
let ele_signum = ele.y.signum();
if last_ele_signum.is_nan() | ele_signum.is_nan() {
continue;
}
if last_ele_signum != ele_signum {
// Do 50 iterations of newton's method, should be more than accurate
let x = {
let mut x1: f64 = last_ele.unwrap().x;
let mut x2: f64;
let mut fail: bool = false;
loop {
x2 = x1 - (self.function.get(x1) / self.function.get_derivative_1(x1));
if !(self.min_x..self.max_x).contains(&x2) {
fail = true;
break;
}
if (x2 - x1).abs() < resolution {
break;
}
x1 = x2;
}
match fail {
true => f64::NAN,
false => x1,
}
};
if !x.is_nan() {
root_list.push(Value::new(x, self.function.get(x)));
}
}
last_ele = Some(*ele);
}
self.output.roots = Some(root_list);
}
// Finds extrema
fn extrema(&mut self) {
let resolution: f64 = (self.pixel_width as f64 / (self.max_x - self.min_x).abs()) as f64;
let mut extrama_list: Vec<Value> = Vec::new();
let mut last_ele: Option<Value> = None;
for ele in self.output.derivative.as_ref().unwrap().iter() {
if last_ele.is_none() {
last_ele = Some(*ele);
continue;
}
let last_ele_signum = last_ele.unwrap().y.signum();
let ele_signum = ele.y.signum();
if last_ele_signum.is_nan() | ele_signum.is_nan() {
continue;
}
if last_ele_signum != ele_signum {
// Do 50 iterations of newton's method, should be more than accurate
let x = {
let mut x1: f64 = last_ele.unwrap().x;
let mut x2: f64;
let mut fail: bool = false;
loop {
x2 = x1
- (self.function.get_derivative_1(x1)
/ self.function.get_derivative_2(x1));
if !(self.min_x..self.max_x).contains(&x2) {
fail = true;
break;
}
if (x2 - x1).abs() < resolution {
break;
}
x1 = x2;
}
match fail {
true => f64::NAN,
false => x1,
}
};
if !x.is_nan() {
extrama_list.push(Value::new(x, self.function.get(x)));
}
}
last_ele = Some(*ele);
}
self.output.extrema = Some(extrama_list);
}
pub fn display(
&mut self, plot_ui: &mut PlotUi, min_x: f64, max_x: f64, pixel_width: usize,
) -> f64 {
if pixel_width != self.pixel_width {
self.output.invalidate_back();
self.output.invalidate_derivative();
self.min_x = min_x;
self.max_x = max_x;
self.pixel_width = pixel_width;
} else if ((min_x != self.min_x) | (max_x != self.max_x)) && self.output.back.is_some() {
let resolution: f64 = self.pixel_width as f64 / (max_x.abs() + min_x.abs());
let back_cache = self.output.back.as_ref().unwrap();
let x_data: SteppedVector = back_cache
.iter()
.map(|ele| ele.x)
.collect::<Vec<f64>>()
.into();
self.output.back = Some(
(0..self.pixel_width)
.map(|x| (x as f64 / resolution as f64) + min_x)
.map(|x| {
if let Some(i) = x_data.get_index(x) {
back_cache[i]
} else {
Value::new(x, self.function.get(x))
}
})
.collect(),
);
// assert_eq!(self.output.back.as_ref().unwrap().len(), self.pixel_width);
let derivative_cache = self.output.derivative.as_ref().unwrap();
let new_data = (0..self.pixel_width)
.map(|x| (x as f64 / resolution as f64) + min_x)
.map(|x| {
if let Some(i) = x_data.get_index(x) {
derivative_cache[i]
} else {
Value::new(x, self.function.get_derivative_1(x))
}
})
.collect();
self.output.derivative = Some(new_data);
} else {
self.output.invalidate_back();
self.output.invalidate_derivative();
self.pixel_width = pixel_width;
}
if self.extrema {
if (min_x != self.min_x) | (max_x != self.max_x) {
self.extrema();
}
} else {
self.output.extrema = None;
}
if self.roots {
if (min_x != self.min_x) | (max_x != self.max_x) {
self.roots();
}
} else {
self.output.roots = None;
}
self.min_x = min_x;
self.max_x = max_x;
let (back_values, integral, derivative) = self.run_back();
self.output.back = Some(back_values);
self.output.integral = integral;
self.output.derivative = derivative;
if self.extrema {
self.extrema();
} else {
self.output.extrema = None;
}
if self.roots {
self.roots();
} else {
self.output.roots = None;
}
self.output.display(
plot_ui,
self.get_func_str(),
&self.function.get_derivative_str(),
(self.integral_min_x - self.integral_max_x).abs() / (self.integral_num as f64),
self.derivative,
)
}
}
#[cfg(test)]
fn verify_function(
integral_num: usize, pixel_width: usize, function: &mut FunctionEntry,
back_values_target: Vec<(f64, f64)>, area_target: f64,
) {
{
let (back_values, bars, derivative) = function.run_back();
assert!(derivative.is_some());
assert!(bars.is_none());
assert_eq!(back_values.len(), pixel_width);
let back_values_tuple: Vec<(f64, f64)> =
back_values.iter().map(|ele| (ele.x, ele.y)).collect();
assert_eq!(back_values_tuple, back_values_target);
}
{
*function = function.clone().integral(true);
let (back_values, bars, derivative) = function.run_back();
assert!(derivative.is_some());
assert!(bars.is_some());
assert_eq!(back_values.len(), pixel_width);
assert_eq!(bars.clone().unwrap().1, area_target);
let vec_bars = bars.unwrap().0;
assert_eq!(vec_bars.len(), integral_num);
let back_values_tuple: Vec<(f64, f64)> =
back_values.iter().map(|ele| (ele.x, ele.y)).collect();
assert_eq!(back_values_tuple, back_values_target);
}
{
let (back_values, bars, derivative) = function.run_back();
assert!(derivative.is_some());
assert!(bars.is_some());
assert_eq!(back_values.len(), pixel_width);
assert_eq!(bars.clone().unwrap().1, area_target);
let bars_unwrapped = bars.unwrap();
assert_eq!(bars_unwrapped.0.iter().len(), integral_num);
}
}
#[test]
fn left_function_test() {
let integral_num = 10;
let pixel_width = 10;
let mut function = FunctionEntry::empty()
.update_riemann(RiemannSum::Left)
.pixel_width(pixel_width)
.integral_num(integral_num)
.integral_bounds(-1.0, 1.0);
let back_values_target = vec![
(-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),
];
let area_target = 0.9600000000000001;
verify_function(
integral_num,
pixel_width,
&mut function,
back_values_target,
area_target,
);
}
#[test]
fn middle_function_test() {
let integral_num = 10;
let pixel_width = 10;
let mut function = FunctionEntry::empty()
.update_riemann(RiemannSum::Middle)
.pixel_width(pixel_width)
.integral_num(integral_num)
.integral_bounds(-1.0, 1.0);
let back_values_target = vec![
(-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),
];
let area_target = 0.92;
verify_function(
integral_num,
pixel_width,
&mut function,
back_values_target,
area_target,
);
}
#[test]
fn right_function_test() {
let integral_num = 10;
let pixel_width = 10;
let mut function = FunctionEntry::empty()
.update_riemann(RiemannSum::Right)
.pixel_width(pixel_width)
.integral_num(integral_num)
.integral_bounds(-1.0, 1.0);
let back_values_target = vec![
(-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),
];
let area_target = 0.8800000000000001;
verify_function(
integral_num,
pixel_width,
&mut function,
back_values_target,
area_target,
);
}