Log-2 Axis Scale Plotting

CHANGELOG.md

@@ -9,6 +9,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [0.8.2](https://github.com/criterion-rs/criterion.rs/compare/criterion-v0.8.1...criterion-v0.8.2) - 2026-02-04
 
+### Changed
+
+- Added support for plots with logarithmic axis with base other than 10 (e.g. log2)
+
 ### Fixed
 
 - don't build alloca on unsupported targets

book/src/user_guide/advanced_configuration.md

@@ -138,7 +138,7 @@ fn do_a_thing(x: u64) {
 
 fn bench(c: &mut Criterion) {
     let plot_config = PlotConfiguration::default()
-        .summary_scale(AxisScale::Logarithmic);
+        .summary_scale(AxisScale::Logarithmic(10.0));
 
     let mut group = c.benchmark_group("log_scale_example");
     group.plot_config(plot_config);

plot/src/axis.rs

@@ -14,7 +14,7 @@ pub struct Properties {
     grids: map::grid::Map<grid::Properties>,
     hidden: bool,
     label: Option<Cow<'static, str>>,
-    logarithmic: bool,
+    scale: Scale,
     range: Option<(f64, f64)>,
     scale_factor: f64,
     tics: Option<String>,
@@ -26,7 +26,7 @@ impl Default for Properties {
             grids: map::grid::Map::new(),
             hidden: false,
             label: None,
-            logarithmic: false,
+            scale: Scale::Linear,
             range: None,
             scale_factor: 1.,
             tics: None,
@@ -103,10 +103,7 @@ impl Set<Scale> for Properties {
     fn set(&mut self, scale: Scale) -> &mut Properties {
         self.hidden = false;
 
-        match scale {
-            Scale::Linear => self.logarithmic = false,
-            Scale::Logarithmic => self.logarithmic = true,
-        }
+        self.scale = scale;
 
         self
     }
@@ -178,8 +175,8 @@ impl Script for (Axis, &Properties) {
             script.push_str(&format!("set {}range [{}:{}]\n", axis_, low, high))
         }
 
-        if properties.logarithmic {
-            script.push_str(&format!("set logscale {}\n", axis_));
+        if let Scale::Logarithmic(base) = properties.scale {
+            script.push_str(&format!("set logscale {} {}\n", axis_, base))
         }
 
         for (grid, properties) in properties.grids.iter() {

plot/src/lib.rs

@@ -853,7 +853,7 @@ pub enum PointType {
 #[derive(Clone, Copy)]
 pub enum Scale {
     Linear,
-    Logarithmic,
+    Logarithmic(f64),
 }
 
 /// Axis scale factor

src/connection.rs

@@ -308,13 +308,13 @@ impl From<&InternalBenchmarkId> for RawBenchmarkId {
 #[derive(Debug, Serialize)]
 pub enum AxisScale {
     Linear,
-    Logarithmic,
+    LogarithmicWithBase(f64),
 }
 impl From<crate::AxisScale> for AxisScale {
     fn from(other: crate::AxisScale) -> Self {
         match other {
             crate::AxisScale::Linear => AxisScale::Linear,
-            crate::AxisScale::Logarithmic => AxisScale::Logarithmic,
+            crate::AxisScale::Logarithmic(base) => AxisScale::LogarithmicWithBase(base),
         }
     }
 }

src/lib.rs

@@ -1323,8 +1323,8 @@ pub enum AxisScale {
     #[default]
     Linear,
 
-    /// Axes scale logarithmically
-    Logarithmic,
+    /// Axes scale logarithmically, with specified base
+    Logarithmic(f64),
 }
 
 /// Contains the configuration options for the plots generated by a particular benchmark
@@ -1334,7 +1334,7 @@ pub enum AxisScale {
 /// use self::criterion::{Bencher, Criterion, PlotConfiguration, AxisScale};
 ///
 /// let plot_config = PlotConfiguration::default()
-///     .summary_scale(AxisScale::Logarithmic);
+///     .summary_scale(AxisScale::Logarithmic(10.0));
 ///
 /// // Using Criterion::default() for simplicity; normally you'd use the macros.
 /// let mut criterion = Criterion::default();

src/plot/gnuplot_backend/summary.rs

@@ -32,15 +32,6 @@ static COMPARISON_COLORS: [Color; NUM_COLORS] = [
     Color::Rgb(0, 255, 127),
 ];
 
-impl AxisScale {
-    fn to_gnuplot(self) -> Scale {
-        match self {
-            AxisScale::Linear => Scale::Linear,
-            AxisScale::Logarithmic => Scale::Logarithmic,
-        }
-    }
-}
-
 #[allow(clippy::explicit_counter_loop)]
 pub(crate) fn line_comparison(
     line_cfg: LinePlotConfig,
@@ -71,7 +62,7 @@ pub(crate) fn line_comparison(
         .set(Title(format!("{}: Comparison", gnuplot_escape(title))))
         .configure(Axis::BottomX, |a| {
             a.set(Label(format!("Input{}", input_suffix)))
-                .set(axis_scale.to_gnuplot())
+                .set(Scale::from(axis_scale))
         });
 
     let mut i = 0;
@@ -92,7 +83,7 @@ pub(crate) fn line_comparison(
         a.configure(Grid::Major, |g| g.show())
             .configure(Grid::Minor, |g| g.hide())
             .set(Label(format!("Average {} ({})", line_cfg.label, unit)))
-            .set(axis_scale.to_gnuplot())
+            .set(Scale::from(axis_scale))
     });
 
     // This assumes the curves are sorted. It also assumes that the benchmark IDs all have numeric
@@ -189,7 +180,7 @@ pub fn violin(
                 .configure(Grid::Minor, |g| g.hide())
                 .set(Range::Limits(0., max * one[0]))
                 .set(Label(format!("Average time ({})", unit)))
-                .set(axis_scale.to_gnuplot())
+                .set(Scale::from(axis_scale))
         })
         .configure(Axis::LeftY, |a| {
             a.set(Label("Input"))

src/plot/mod.rs

@@ -2,10 +2,13 @@ mod gnuplot_backend;
 #[cfg(feature = "plotters")]
 mod plotters_backend;
 
+use criterion_plot::Scale;
 pub(crate) use gnuplot_backend::Gnuplot;
 #[cfg(feature = "plotters")]
 pub(crate) use plotters_backend::PlottersBackend;
 
+use crate::AxisScale;
+
 use {
     crate::{
         estimate::Statistic,
@@ -34,6 +37,15 @@ pub(crate) struct PlotContext<'a> {
     pub(crate) is_thumbnail: bool,
 }
 
+impl From<AxisScale> for Scale {
+    fn from(value: AxisScale) -> Self {
+        match value {
+            AxisScale::Linear => Scale::Linear,
+            AxisScale::Logarithmic(base) => Scale::Logarithmic(base),
+        }
+    }
+}
+
 impl<'a> PlotContext<'a> {
     pub fn size(mut self, s: Option<criterion_plot::Size>) -> PlotContext<'a> {
         if let Some(s) = s {

src/plot/plotters_backend/summary.rs

@@ -1,6 +1,7 @@
 use {
     super::*,
     crate::AxisScale,
+    criterion_plot::Scale,
     itertools::Itertools,
     plotters::coord::{
         ranged1d::{AsRangedCoord, ValueFormatter as PlottersValueFormatter},
@@ -41,8 +42,8 @@ pub(crate) fn line_comparison(
         .titled(&format!("{}: Comparison", title), (DEFAULT_FONT, 20))
         .unwrap();
 
-    match axis_scale {
-        AxisScale::Linear => draw_line_comparison_figure(
+    match Scale::from(axis_scale) {
+        Scale::Linear => draw_line_comparison_figure(
             line_cfg,
             root_area,
             unit,
@@ -51,12 +52,12 @@ pub(crate) fn line_comparison(
             value_type,
             series_data,
         ),
-        AxisScale::Logarithmic => draw_line_comparison_figure(
+        Scale::Logarithmic(base) => draw_line_comparison_figure(
             line_cfg,
             root_area,
             unit,
-            x_range.log_scale(),
-            y_range.log_scale(),
+            x_range.log_scale().base(base),
+            y_range.log_scale().base(base),
             value_type,
             series_data,
         ),
@@ -223,10 +224,16 @@ pub fn violin(
         .titled(&format!("{}: Violin plot", title), (DEFAULT_FONT, 20))
         .unwrap();
 
-    match axis_scale {
-        AxisScale::Linear => draw_violin_figure(root_area, unit, x_range, y_range, kdes),
-        AxisScale::Logarithmic => {
-            draw_violin_figure(root_area, unit, x_range.log_scale(), y_range, kdes);
+    match Scale::from(axis_scale) {
+        Scale::Linear => draw_violin_figure(root_area, unit, x_range, y_range, kdes),
+        Scale::Logarithmic(base) => {
+            draw_violin_figure(
+                root_area,
+                unit,
+                x_range.log_scale().base(base),
+                y_range,
+                kdes,
+            );
         }
     }
 }