diff options
Diffstat (limited to 'src/series/histogram.rs')
| -rw-r--r-- | src/series/histogram.rs | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/series/histogram.rs b/src/series/histogram.rs new file mode 100644 index 0000000..75c2fb2 --- /dev/null +++ b/src/series/histogram.rs @@ -0,0 +1,213 @@ +use std::collections::{hash_map::IntoIter as HashMapIter, HashMap}; +use std::hash::Hash; +use std::marker::PhantomData; +use std::ops::AddAssign; + +use crate::chart::ChartContext; +use crate::coord::{DiscreteRanged, Ranged, RangedCoord}; +use crate::drawing::DrawingBackend; +use crate::element::Rectangle; +use crate::style::{Color, ShapeStyle, GREEN}; + +pub trait HistogramType {} +pub struct Vertical; +pub struct Horizontal; + +impl HistogramType for Vertical {} +impl HistogramType for Horizontal {} + +/// The series that aggregate data into a histogram +pub struct Histogram<'a, BR, A, Tag = Vertical> +where + BR: DiscreteRanged, + BR::ValueType: Eq + Hash, + A: AddAssign<A> + Default, + Tag: HistogramType, +{ + style: Box<dyn Fn(&BR::ValueType, &A) -> ShapeStyle + 'a>, + margin: u32, + iter: HashMapIter<BR::ValueType, A>, + baseline: Box<dyn Fn(BR::ValueType) -> A + 'a>, + br_param: BR::RangeParameter, + _p: PhantomData<(BR, Tag)>, +} + +impl<'a, BR, A, Tag> Histogram<'a, BR, A, Tag> +where + BR: DiscreteRanged, + BR::ValueType: Eq + Hash, + A: AddAssign<A> + Default + 'a, + Tag: HistogramType, +{ + fn empty(br_param: BR::RangeParameter) -> Self { + Self { + style: Box::new(|_, _| GREEN.filled()), + margin: 5, + iter: HashMap::new().into_iter(), + baseline: Box::new(|_| A::default()), + br_param, + _p: PhantomData, + } + } + /// Set the style of the histogram + pub fn style<S: Into<ShapeStyle>>(mut self, style: S) -> Self { + let style = style.into(); + self.style = Box::new(move |_, _| style.clone()); + self + } + + /// Set the style of histogram using a lambda function + pub fn style_func( + mut self, + style_func: impl Fn(&BR::ValueType, &A) -> ShapeStyle + 'a, + ) -> Self { + self.style = Box::new(style_func); + self + } + + /// Set the baseline of the histogram + pub fn baseline(mut self, baseline: A) -> Self + where + A: Clone, + { + self.baseline = Box::new(move |_| baseline.clone()); + self + } + + /// Set a function that defines variant baseline + pub fn baseline_func(mut self, func: impl Fn(BR::ValueType) -> A + 'a) -> Self { + self.baseline = Box::new(func); + self + } + + /// Set the margin for each bar + pub fn margin(mut self, value: u32) -> Self { + self.margin = value; + self + } + + /// Set the data iterator + pub fn data<I: IntoIterator<Item = (BR::ValueType, A)>>(mut self, iter: I) -> Self { + let mut buffer = HashMap::<BR::ValueType, A>::new(); + for (x, y) in iter.into_iter() { + *buffer.entry(x).or_insert_with(Default::default) += y; + } + self.iter = buffer.into_iter(); + self + } +} + +pub trait UseDefaultParameter: Default { + fn new() -> Self { + Default::default() + } +} + +impl UseDefaultParameter for () {} + +impl<'a, BR, A> Histogram<'a, BR, A, Vertical> +where + BR: DiscreteRanged, + BR::ValueType: Eq + Hash, + A: AddAssign<A> + Default + 'a, +{ + /// Create a new histogram series. + /// + /// - `iter`: The data iterator + /// - `margin`: The margin between bars + /// - `style`: The style of bars + /// + /// Returns the newly created histogram series + #[allow(clippy::redundant_closure)] + pub fn new<S: Into<ShapeStyle>, I: IntoIterator<Item = (BR::ValueType, A)>>( + iter: I, + margin: u32, + style: S, + ) -> Self + where + BR::RangeParameter: UseDefaultParameter, + { + let mut buffer = HashMap::<BR::ValueType, A>::new(); + for (x, y) in iter.into_iter() { + *buffer.entry(x).or_insert_with(Default::default) += y; + } + let style = style.into(); + Self { + style: Box::new(move |_, _| style.clone()), + margin, + iter: buffer.into_iter(), + baseline: Box::new(|_| A::default()), + br_param: BR::RangeParameter::new(), + _p: PhantomData, + } + } + + pub fn vertical<ACoord, DB: DrawingBackend + 'a>( + parent: &ChartContext<DB, RangedCoord<BR, ACoord>>, + ) -> Self + where + ACoord: Ranged<ValueType = A>, + { + let dp = parent.as_coord_spec().x_spec().get_range_parameter(); + + Self::empty(dp) + } +} + +impl<'a, BR, A> Histogram<'a, BR, A, Horizontal> +where + BR: DiscreteRanged, + BR::ValueType: Eq + Hash, + A: AddAssign<A> + Default + 'a, +{ + pub fn horizontal<ACoord, DB: DrawingBackend>( + parent: &ChartContext<DB, RangedCoord<ACoord, BR>>, + ) -> Self + where + ACoord: Ranged<ValueType = A>, + { + let dp = parent.as_coord_spec().y_spec().get_range_parameter(); + Self::empty(dp) + } +} + +impl<'a, BR, A> Iterator for Histogram<'a, BR, A, Vertical> +where + BR: DiscreteRanged, + BR::ValueType: Eq + Hash, + A: AddAssign<A> + Default, +{ + type Item = Rectangle<(BR::ValueType, A)>; + fn next(&mut self) -> Option<Self::Item> { + if let Some((x, y)) = self.iter.next() { + let nx = BR::next_value(&x, &self.br_param); + let base = (self.baseline)(BR::previous_value(&nx, &self.br_param)); + let style = (self.style)(&x, &y); + let mut rect = Rectangle::new([(x, y), (nx, base)], style); + rect.set_margin(0, 0, self.margin, self.margin); + return Some(rect); + } + None + } +} + +impl<'a, BR, A> Iterator for Histogram<'a, BR, A, Horizontal> +where + BR: DiscreteRanged, + BR::ValueType: Eq + Hash, + A: AddAssign<A> + Default, +{ + type Item = Rectangle<(A, BR::ValueType)>; + fn next(&mut self) -> Option<Self::Item> { + if let Some((y, x)) = self.iter.next() { + let ny = BR::next_value(&y, &self.br_param); + // With this trick we can avoid the clone trait bound + let base = (self.baseline)(BR::previous_value(&ny, &self.br_param)); + let style = (self.style)(&y, &x); + let mut rect = Rectangle::new([(x, y), (base, ny)], style); + rect.set_margin(self.margin, self.margin, 0, 0); + return Some(rect); + } + None + } +} |