This commit is contained in:
Simon Gardling 2022-02-11 09:52:33 -05:00
parent a56165236e
commit be2d6a2f71
2 changed files with 10 additions and 16 deletions

View File

@ -5,11 +5,11 @@ use web_sys::HtmlCanvasElement;
use meval::Expr;
/// Draw power function f(x) = x^power.
pub fn draw(element: HtmlCanvasElement, func_str: &str, minX: f32, maxX: f32, minY: f32, maxY: f32, num_interval: usize, resolution: i32) -> DrawResult<(impl Fn((i32, i32))-> Option<(f32, f32)>, f32)> {
pub fn draw(element: HtmlCanvasElement, func_str: &str, min_x: f32, max_x: f32, min_y: f32, max_y: f32, num_interval: usize, resolution: i32) -> DrawResult<(impl Fn((i32, i32))-> Option<(f32, f32)>, f32)> {
let expr: Expr = func_str.parse().unwrap();
let func = expr.bind("x").unwrap();
let absrange = (maxX-minX).abs();
let absrange = (max_x-min_x).abs();
let step = absrange/(num_interval as f32);
let backend = CanvasBackend::with_canvas_object(element).unwrap();
@ -23,18 +23,18 @@ pub fn draw(element: HtmlCanvasElement, func_str: &str, minX: f32, maxX: f32, mi
.caption(format!("y={}", func_str), font)
.x_label_area_size(30 as f32)
.y_label_area_size(30 as f32)
.build_cartesian_2d(minX..maxX, minY..maxY)?;
.build_cartesian_2d(min_x..max_x, min_y..max_y)?;
chart.configure_mesh().x_labels(3).y_labels(3).draw()?;
let data = (1..=resolution)
.map(|x| (((x as f32/resolution as f32))*(&absrange))+&minX)
.map(|x| (((x as f32/resolution as f32))*(&absrange))+&min_x)
.map(|x| (x, func(x as f64) as f32))
.filter(|(_,y)| &minY <= y && y <= &maxY);
.filter(|(_,y)| &min_y <= y && y <= &max_y);
chart.draw_series(LineSeries::new(data, &RED))?;
let (data2, area) = integral_rectangles(minX, minY, maxY, step, num_interval, &func); // Get rectangle coordinates and the total area
let (data2, area) = integral_rectangles(min_x, step, num_interval, &func); // Get rectangle coordinates and the total area
// Draw rectangles
chart.draw_series(data2.iter().map(|(x1, x2, y)| Rectangle::new([(*x2, *y), (*x1, 0.0)], &BLUE)))?;
@ -46,7 +46,7 @@ pub fn draw(element: HtmlCanvasElement, func_str: &str, minX: f32, maxX: f32, mi
// Creates and does the math for creating all the rectangles under the graph
#[inline(always)]
fn integral_rectangles(minX: f32, minY: f32, maxY: f32, step: f32, num_interval: usize, func: &dyn Fn(f64) -> f64) -> (Vec<(f32, f32, f32)>, f32) {
fn integral_rectangles(min_x: f32, step: f32, num_interval: usize, func: &dyn Fn(f64) -> f64) -> (Vec<(f32, f32, f32)>, f32) {
let mut area: f32 = 0.0; // sum of all rectangles' areas
let mut tmp1: f32; // Top left Y value that's tested
let mut tmp2: f32; // Top right Y value that's tested
@ -55,7 +55,7 @@ fn integral_rectangles(minX: f32, minY: f32, maxY: f32, step: f32, num_interval:
let mut x: f32; // X value of the left side of the rectangle
let mut data2: Vec<(f32, f32, f32)> = Vec::new();
for e in 0..num_interval {
x = ((e as f32)*step)+minX;
x = ((e as f32)*step)+min_x;
if x > 0.0 {
x2 = x+step;

View File

@ -23,8 +23,8 @@ pub struct Point {
#[wasm_bindgen]
impl Chart {
pub fn draw(canvas: HtmlCanvasElement, func: &str, minX: f32, maxX: f32, minY: f32, maxY: f32, num_interval: usize, resolution: i32) -> Result<Chart, JsValue> {
let output = func_plot::draw(canvas, func, minX, maxX, minY, maxY, num_interval, resolution).map_err(|err| err.to_string())?;
pub fn draw(canvas: HtmlCanvasElement, func: &str, min_x: f32, max_x: f32, min_y: f32, max_y: f32, num_interval: usize, resolution: i32) -> Result<Chart, JsValue> {
let output = func_plot::draw(canvas, func, min_x, max_x, min_y, max_y, num_interval, resolution).map_err(|err| err.to_string())?;
let map_coord = output.0;
Ok(Chart {
convert: Box::new(move |coord| map_coord(coord).map(|(x, y)| (x.into(), y.into()))),
@ -36,12 +36,6 @@ impl Chart {
return Ok(self.area);
}
// Does actual calculation of antiderivative
// pub fn actual_area(power: f32, minX: f32, maxX: f32) -> Result<f32, JsValue> {
// let newpower = power + 1.0;
// return Ok((maxX.powf(newpower as f32)/newpower) - (minX.powf(newpower as f32)/newpower));
// }
pub fn coord(&self, x: i32, y: i32) -> Option<Point> {
(self.convert)((x, y)).map(|(x, y)| Point { x, y })
}