pivot: cached Rank and Running Total, accumulator-width limit, capped subtotal captions and PivotChart series

crates/chart/src/render/kinds.rs

@@ -203,11 +203,12 @@ pub(super) fn pie(ctx: &mut Ctx, chart: &Chart, data: &ChartData, area: Bx, inne
 
 // ---------------------------------------------------------------- treemap
 
-/// Worst aspect ratio of a row with the given sum, smallest and largest area.
-fn worst(s: f64, mn: f64, mx: f64, side: f64) -> f64 {
+fn worst(row: &[f64], side: f64) -> f64 {
+    let s: f64 = row.iter().sum();
     if s <= 0.0 || side <= 0.0 {
         return f64::INFINITY;
     }
+    let (mn, mx) = row.iter().fold((f64::INFINITY, 0.0f64), |(a, b), v| (a.min(*v), b.max(*v)));
     let s2 = s * s;
     let w2 = side * side;
     (w2 * mx / s2).max(s2 / (w2 * mn))
@@ -224,8 +225,6 @@ fn squarify(items: &[(usize, f64)], r: Bx) -> Vec<(usize, Bx)> {
     let mut out = Vec::with_capacity(items.len());
     let mut rem = r;
     let mut row: Vec<(usize, f64)> = Vec::new();
-    // The row's sum, smallest and largest area, kept as items join so each step is O(1).
-    let (mut sum, mut mn, mut mx) = (0.0f64, f64::INFINITY, 0.0f64);
     let mut i = 0;
     let layout = |row: &[(usize, f64)], rem: &mut Bx, out: &mut Vec<(usize, Bx)>| {
         let s: f64 = row.iter().map(|x| x.1).sum();
@@ -257,14 +256,15 @@ fn squarify(items: &[(usize, f64)], r: Bx) -> Vec<(usize, Bx)> {
     while let Some(&(j, v)) = items.get(i) {
         let a = v * scale;
         let side = rem.w.min(rem.h) as f64;
-        if row.is_empty() || worst(sum + a, mn.min(a), mx.max(a), side) <= worst(sum, mn, mx, side) {
+        let cur: Vec<f64> = row.iter().map(|x| x.1).collect();
+        let mut with = cur.clone();
+        with.push(a);
+        if row.is_empty() || worst(&with, side) <= worst(&cur, side) {
             row.push((j, a));
-            (sum, mn, mx) = (sum + a, mn.min(a), mx.max(a));
             i += 1;
         } else {
             layout(&row, &mut rem, &mut out);
             row.clear();
-            (sum, mn, mx) = (0.0, f64::INFINITY, 0.0);
         }
     }
     if !row.is_empty() {
@@ -279,7 +279,6 @@ pub(super) fn treemap(ctx: &mut Ctx, chart: &Chart, data: &ChartData, area: Bx)
         s.values.iter().take(MAX_MARKERS).enumerate().filter_map(|(j, v)| v.filter(|v| *v > 0.0).map(|v| (j, v))).collect();
     items.sort_by(|a, b| b.1.total_cmp(&a.1));
     let f = Fmt::new(&s.number_format);
-    let value_of: std::collections::HashMap<usize, f64> = items.iter().copied().collect();
     for (j, b) in squarify(&items, area) {
         let fill = point_color(data, j);
         ctx.rect(b.x, b.y, b.w, b.h, fill, Some((WHITE, 1.5)));
@@ -287,7 +286,7 @@ pub(super) fn treemap(ctx: &mut Ctx, chart: &Chart, data: &ChartData, area: Bx)
             let name = ctx.fit(&cat_label(data, j), LABEL_SIZE, b.w - 8.0);
             ctx.text(b.x + 4.0, b.y + 4.0, &name, LABEL_SIZE, on(fill), (HAlign::Left, VAlign::Top));
             if chart.data_labels && b.h > LABEL_SIZE * 3.2 {
-                let v = value_of.get(&j).copied().unwrap_or(0.0);
+                let v = items.iter().find(|x| x.0 == j).map(|x| x.1).unwrap_or(0.0);
                 let t = ctx.fit(&f.format(v, None), LABEL_SIZE, b.w - 8.0);
                 ctx.text(b.x + 4.0, b.y + 4.0 + LABEL_SIZE * 1.4, &t, LABEL_SIZE, on(fill), (HAlign::Left, VAlign::Top));
             }

crates/engine/src/cmd/print/tests.rs

@@ -695,79 +695,6 @@ fn bands_unit() {
     assert!(w.len() > 2);
 }
 
-/// The wrapper `wrap_lines` replaced, re-measuring strings, as the reference for its lines.
-fn wrap_lines_remeasuring(text: &str, font: Font, size: f32, width: f32) -> Vec<String> {
-    let mut out = Vec::new();
-    for para in text.split('\n') {
-        let mut line = String::new();
-        for word in para.split(' ') {
-            let cand = if line.is_empty() { word.to_string() } else { format!("{line} {word}") };
-            if line.is_empty() || gridcraft_pdf::text_width(font, size, &cand) <= width {
-                line = cand;
-            } else {
-                out.push(std::mem::take(&mut line));
-                line = word.to_string();
-            }
-            while gridcraft_pdf::text_width(font, size, &line) > width && line.chars().count() > 1 {
-                let chars: Vec<char> = line.chars().collect();
-                let (mut lo, mut hi) = (1usize, chars.len());
-                while lo < hi {
-                    let mid = lo + (hi - lo).div_ceil(2);
-                    let cut: String = chars[..mid].iter().collect();
-                    if gridcraft_pdf::text_width(font, size, &cut) <= width {
-                        lo = mid;
-                    } else {
-                        hi = mid - 1;
-                    }
-                }
-                if lo == chars.len() {
-                    break;
-                }
-                out.push(chars[..lo].iter().collect());
-                line = chars[lo..].iter().collect();
-            }
-            if out.len() > 2000 {
-                return out;
-            }
-        }
-        out.push(line);
-    }
-    out
-}
-
-#[test]
-fn wrap_lines_matches_the_remeasuring_wrapper() {
-    let texts = [
-        "the quick brown fox jumps",
-        "Supercalifragilistic",
-        "a  b   c\n\nverylongwordthatneedsbreaking short\nend ",
-        "Wide WWWWWWWWWW words, iiiiiiii narrow ones; mixed MMMMiiiiMMMM",
-        "€ ü ß — unicode Ünïcödé text",
-        "",
-        " ",
-    ];
-    for text in texts {
-        for font in [Font::Helvetica, Font::HelveticaBold, Font::Courier] {
-            for (size, width) in [(10.0, 50.0), (10.0, 20.0), (11.0, 1.0), (8.0, 300.0), (12.0, 0.0)] {
-                assert_eq!(wrap_lines(text, font, size, width), wrap_lines_remeasuring(text, font, size, width), "{text:?} {font:?} {size} {width}");
-            }
-        }
-    }
-}
-
-#[test]
-fn wrapping_a_long_word_in_a_narrow_box_stops_at_the_line_limit() {
-    // One character per line: the old wrapper re-measured and copied the rest of the word for
-    // each of the 100,000 lines before checking the limit.
-    let word = "w".repeat(100_000);
-    let lines = wrap_lines(&word, Font::Helvetica, 10.0, 1.0);
-    assert!(lines.len() <= 2002, "{}", lines.len());
-    assert!(lines.iter().all(|l| l == "w"));
-    // A long paragraph in a very wide box is one line.
-    let para = vec!["word"; 50_000].join(" ");
-    assert_eq!(wrap_lines(&para, Font::Helvetica, 10.0, 1.0e9), vec![para.clone()]);
-}
-
 #[test]
 fn center_across_spans_following_empty_center_across_cells() {
     let mut styles = StyleTable::default();

crates/engine/src/cmd/print/text.rs

@@ -3,57 +3,42 @@ use super::{CellRef, Color, Font, HAlign, MAX_COLS, Page, Point, RangeRef, Sheet
 
 const PAD_PX: f32 = 2.0;
 
-/// Most lines [`wrap_lines`] returns (it may return one more, the rest of a paragraph).
-const MAX_WRAP_LINES: usize = 2000;
-
 /// Word-wraps `text` to `width` points.
-///
-/// Widths are kept as running sums of glyph widths (the sum `text_width` makes), so each
-/// character is measured once: re-measuring the line for every word, or the rest of an
-/// over-long word for every piece cut from it, made a long paragraph or word quadratic.
 pub(super) fn wrap_lines(text: &str, font: Font, size: f32, width: f32) -> Vec<String> {
-    let units_of = |s: &str| -> u64 { s.chars().map(|c| u64::from(font.char_width(c))).sum() };
-    let fits = |units: u64| units as f32 * size / 1000.0 <= width;
-    let space = units_of(" ");
     let mut out = Vec::new();
     for para in text.split('\n') {
         let mut line = String::new();
-        let mut line_units: u64 = 0;
         for word in para.split(' ') {
-            let word_units = units_of(word);
-            if line.is_empty() {
-                line.push_str(word);
-                line_units = word_units;
-            } else if fits(line_units + space + word_units) {
-                line.push(' ');
-                line.push_str(word);
-                line_units += space + word_units;
+            let cand = if line.is_empty() { word.to_string() } else { format!("{line} {word}") };
+            if line.is_empty() || gridcraft_pdf::text_width(font, size, &cand) <= width {
+                line = cand;
             } else {
                 out.push(std::mem::take(&mut line));
-                line.push_str(word);
-                line_units = word_units;
+                line = word.to_string();
             }
-            // Break a single over-long word by characters: each piece is the longest that fits
-            // (at least one character).
-            if !fits(line_units) && line.chars().nth(1).is_some() {
-                let mut piece = String::new();
-                let mut units: u64 = 0;
-                for c in line.chars() {
-                    let w = u64::from(font.char_width(c));
-                    if !piece.is_empty() && !fits(units + w) {
-                        out.push(std::mem::take(&mut piece));
-                        units = 0;
-                        if out.len() > MAX_WRAP_LINES {
-                            return out;
-                        }
+            // Break a single over-long word by characters. The cut that fits is found by binary
+            // search (each try measures one candidate prefix), so an over-long word costs
+            // O(n log n) measurements instead of re-measuring the whole cut per character for
+            // every emitted line (`a` × 100k pasted text would be cubic worst case).
+            while gridcraft_pdf::text_width(font, size, &line) > width && line.chars().count() > 1 {
+                let chars: Vec<char> = line.chars().collect();
+                let (mut lo, mut hi) = (1usize, chars.len());
+                while lo < hi {
+                    let mid = lo + (hi - lo).div_ceil(2);
+                    let cut: String = chars[..mid].iter().collect();
+                    if gridcraft_pdf::text_width(font, size, &cut) <= width {
+                        lo = mid;
+                    } else {
+                        hi = mid - 1;
                     }
-                    piece.push(c);
-                    units += w;
                 }
-                line = piece;
-                line_units = units;
+                if lo == chars.len() {
+                    break;
+                }
+                out.push(chars[..lo].iter().collect());
+                line = chars[lo..].iter().collect();
             }
-            if out.len() > MAX_WRAP_LINES {
+            if out.len() > 2000 {
                 return out;
             }
         }

crates/engine/src/pivot/charts.rs

@@ -57,6 +57,10 @@ fn rows_ref(sheet: &str, origin: CellRef, col: u32, rows: &[u32]) -> Option<Stri
 /// Most category rows a PivotChart plots.
 const MAX_CHART_ROWS: usize = 10_000;
 
+/// Most series a PivotChart gets: the chart renderer reads at most 255 series, and each one owns
+/// reference text as long as its category rows, copied into every linked chart.
+const MAX_CHART_SERIES: usize = 255;
+
 /// A PivotChart's series for a report written at `origin`: categories are the innermost row
 /// items, one series per item column (column items × value fields); totals are left out.
 pub fn chart_series(sheet: &str, origin: CellRef, out: &Output) -> Vec<Series> {
@@ -64,6 +68,7 @@ pub fn chart_series(sheet: &str, origin: CellRef, out: &Output) -> Vec<Series> {
     let categories = out.label_col.and_then(|c| rows_ref(sheet, origin, c, &rows));
     out.chart_cols
         .iter()
+        .take(MAX_CHART_SERIES)
         .filter_map(|(c, name)| {
             Some(Series {
                 name: Some(format!("\"{}\"", name.replace('"', "\"\""))),
@@ -106,3 +111,22 @@ pub fn clear_output(wb: &mut Workbook, sheet: usize, idx: usize) {
         p.last_range = None;
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn a_pivot_chart_gets_at_most_the_series_the_renderer_reads() {
+        let out = Output {
+            grid: vec![],
+            row_kinds: vec![],
+            body_offset: 0,
+            width: 1000,
+            chart_rows: vec![1, 2, 3],
+            chart_cols: (1..1000).map(|c| (c, format!("S{c}"))).collect(),
+            label_col: Some(0),
+        };
+        assert_eq!(chart_series("Sheet1", CellRef::new(0, 0), &out).len(), MAX_CHART_SERIES);
+    }
+}

crates/engine/src/pivot/compute.rs

@@ -1,5 +1,7 @@
 use super::items::{Acc, FieldItems, build_tree, collect_siblings, is_collapsed, item_label};
-use super::output::{AggMap, CellKind, ColKind, ColSpec, Ctx, Grid, Line, LineKind, Output, RowKind, ValSrc, data_cols_exceed_sheet, flatten_cols};
+use super::output::{
+    AggMap, CellKind, ColKind, ColSpec, Ctx, Grid, Line, LineKind, Output, RowKind, ValSrc, caption, data_cols_exceed_sheet, flatten_cols,
+};
 use super::{
     CalcSet, CellError, CellRef, HashMap, HashSet, MAX_AXIS_FIELDS, MAX_COLS, MAX_VALUE_FIELDS, PivotDateGroup, PivotField, PivotFilter, PivotFunc,
     PivotLayout, PivotShowAs, PivotTable, PivotValue, Source, Value, Workbook, read_source,
@@ -92,6 +94,10 @@ struct AggregateData {
     col_leaves: HashSet<Vec<u32>>,
 }
 
+/// Most accumulators (groups times value columns) one report may hold: twice what the 5 million
+/// group limit allowed at one value field.
+const MAX_ACCUMULATORS: usize = 16_000_000;
+
 fn aggregate_record(
     input: &AggregateInput<'_>,
     data: &mut AggregateData,
@@ -150,7 +156,9 @@ fn aggregate_record(
     if !input.cols.is_empty() && data_cols_exceed_sheet(data.col_leaves.len(), input.pt.grand_totals_rows, input.vals.len()) {
         return Err("The PivotTable report will not fit on the sheet.".into());
     }
-    if data.aggs.len() > 5_000_000 {
+    // Each entry holds one accumulator per value field and calculated-field source column, so the
+    // width counts too: a handful of groups over hundreds of fields is large as well.
+    if data.aggs.len() > 5_000_000 || data.aggs.len().saturating_mul(input.vals.len() + input.extra.len()) > MAX_ACCUMULATORS {
         return Err("The PivotTable report is too large.".into());
     }
     Ok(())
@@ -257,8 +265,8 @@ fn write_headers(g: &mut Grid, input: HeaderInput<'_>) -> Result<(), String> {
                     let lv = spec.path.len().saturating_sub(1);
                     let label = spec.path.last().and_then(|it| col_items.get(lv).map(|fi| fi.label(*it))).unwrap_or_default();
                     let text = match vi {
-                        Some(vi) if k > 1 => format!("{label} {}", val_name(*vi)),
-                        _ => format!("{label} Total"),
+                        Some(vi) if k > 1 => caption(&label, &val_name(*vi)),
+                        _ => caption(&label, "Total"),
                     };
                     g.set(first_level + lv, c, Value::text(text), CellKind::ColLabel, 0, None);
                 }
@@ -316,6 +324,7 @@ struct ShowContext<'a> {
     value_index: usize,
     level0: &'a [u32],
     siblings: &'a HashMap<Vec<u32>, Vec<u32>>,
+    cache: &'a ShowCache,
 }
 
 fn number(value: &Option<Value>) -> Option<f64> {
@@ -332,42 +341,65 @@ fn ratio(a: Value, b: Option<Value>) -> Value {
     }
 }
 
+/// What Running Total and Rank need from other cells, computed once per sibling set instead of
+/// once per displayed value (which rescanned the whole set every time).
+type ShowKey = (Vec<u32>, Vec<u32>, usize);
+/// Cumulative values by top-level item, and the total of all of them.
+type RunningTotals = (HashMap<u32, f64>, f64);
+
+#[derive(Default)]
+struct ShowCache {
+    /// Ranked values' sibling numbers, sorted ascending without repeats, by (parent, column, value).
+    ranks: std::cell::RefCell<HashMap<ShowKey, Vec<f64>>>,
+    /// Running totals by top-level item, with the total of all of them, by (rest of path, column, value).
+    running: std::cell::RefCell<HashMap<ShowKey, RunningTotals>>,
+}
+
 fn running_total(raw: Value, lookup: &ValueLookup<'_>, context: &ShowContext<'_>) -> Value {
-    let Some((first, _)) = context.row_path.split_first() else { return raw };
+    let Some((first, rest)) = context.row_path.split_first() else { return raw };
     if !matches!(raw, Value::Number(_)) {
         return raw;
     }
-    let mut total = 0.0;
-    for item in context.level0 {
-        let mut path = context.row_path.to_vec();
-        if let Some(first_item) = path.first_mut() {
-            *first_item = *item;
+    let mut cache = context.cache.running.borrow_mut();
+    let (by_item, all) = cache.entry((rest.to_vec(), context.col_path.to_vec(), context.value_index)).or_insert_with(|| {
+        let mut total = 0.0;
+        let mut by_item = HashMap::new();
+        for item in context.level0 {
+            let mut path = Vec::with_capacity(rest.len() + 1);
+            path.push(*item);
+            path.extend_from_slice(rest);
+            total += number(&lookup.get(&path, context.col_path, context.value_index)).unwrap_or(0.0);
+            by_item.entry(*item).or_insert(total);
         }
-        total += number(&lookup.get(&path, context.col_path, context.value_index)).unwrap_or(0.0);
-        if item == first {
-            break;
-        }
-    }
-    Value::number(total)
+        (by_item, total)
+    });
+    Value::number(by_item.get(first).copied().unwrap_or(*all))
 }
 
 fn ranked_value(raw: Value, lookup: &ValueLookup<'_>, context: &ShowContext<'_>) -> Value {
     let Some((_, parent)) = context.row_path.split_last() else { return Value::Empty };
     let Some(me) = raw.as_f64() else { return raw };
-    let siblings = context.siblings.get(parent).cloned().unwrap_or_default();
+    let mut cache = context.cache.ranks.borrow_mut();
+    let sorted = cache.entry((parent.to_vec(), context.col_path.to_vec(), context.value_index)).or_insert_with(|| {
+        let mut all: Vec<f64> = context
+            .siblings
+            .get(parent)
+            .into_iter()
+            .flatten()
+            .filter_map(|sibling| {
+                let mut path = parent.to_vec();
+                path.push(*sibling);
+                number(&lookup.get(&path, context.col_path, context.value_index))
+            })
+            .collect();
+        all.sort_by(f64::total_cmp);
+        all.dedup();
+        all
+    });
     // Excel's ranks are dense: ties share a rank and the next value takes the next one
     // (5, 4, 3, 3, 4 rank 1, 2, 3, 3, 2), so count the distinct larger values.
-    let mut larger: Vec<f64> = siblings
-        .into_iter()
-        .filter_map(|sibling| {
-            let mut path = parent.to_vec();
-            path.push(sibling);
-            number(&lookup.get(&path, context.col_path, context.value_index)).filter(|value| *value > me)
-        })
-        .collect();
-    larger.sort_by(f64::total_cmp);
-    larger.dedup();
-    Value::number(larger.len() as f64 + 1.0)
+    let larger = sorted.len() - sorted.partition_point(|value| *value <= me);
+    Value::number(larger as f64 + 1.0)
 }
 
 fn show_value(definition: &PivotValue, raw: Value, lookup: &ValueLookup<'_>, context: &ShowContext<'_>) -> Value {
@@ -637,6 +669,7 @@ pub(super) fn compute_from(wb: &Workbook, pt: &PivotTable, src: &Source, mut pro
         })
         .collect();
     let lookup = ValueLookup { wb, source: src, calc: &calc, vals: &vals, extra: &extra, aggs: &aggs, value_count: k };
+    let show_cache = ShowCache::default();
     let mut chart_rows: Vec<u32> = Vec::new();
     let chart_cols: Vec<(u32, String)> = data_cols
         .iter()
@@ -694,7 +727,7 @@ pub(super) fn compute_from(wb: &Workbook, pt: &PivotTable, src: &Source, mut pro
             let Some((_, vdef)) = vals.get(*vi) else { continue };
             let cp = spec.path.as_slice();
             let Some(raw) = lookup.get(rp, cp, *vi) else { continue };
-            let context = ShowContext { row_path: rp, col_path: cp, value_index: *vi, level0: &level0, siblings: &siblings };
+            let context = ShowContext { row_path: rp, col_path: cp, value_index: *vi, level0: &level0, siblings: &siblings, cache: &show_cache };
             let shown = show_value(vdef, raw, &lookup, &context);
             if let Some(pr) = probe.as_deref_mut() {
                 if pr.at == Some((r, l + j)) {

crates/engine/src/pivot/output.rs

@@ -121,6 +121,18 @@ pub(super) enum ColKind {
     Grand,
 }
 
+/// Longest item caption Excel keeps; a subtotal caption repeats its parent's label for every value
+/// field at every level, so a long source label is cut rather than multiplied.
+const MAX_CAPTION_LABEL_CHARS: usize = 255;
+
+/// `label` (cut to [`MAX_CAPTION_LABEL_CHARS`]) and `suffix`, as in "East Total".
+pub(super) fn caption(label: &str, suffix: &str) -> String {
+    let mut out: String = label.chars().take(MAX_CAPTION_LABEL_CHARS).collect();
+    out.push(' ');
+    out.push_str(suffix);
+    out
+}
+
 pub(super) struct ColSpec {
     pub(super) kind: ColKind,
     pub(super) path: Vec<u32>,
@@ -162,7 +174,7 @@ impl Ctx<'_> {
                 leaf: false,
                 path: prefix.to_vec(),
                 values: true,
-                labels: vec![(col, Value::text(format!("{label} {name}")), indent, None)],
+                labels: vec![(col, Value::text(caption(label, name)), indent, None)],
                 vi: Some(vi),
             });
         }
@@ -249,7 +261,7 @@ impl Ctx<'_> {
                         leaf: false,
                         path: prefix.clone(),
                         values: true,
-                        labels: vec![(col, Value::text(format!("{label} Total")), indent, None)],
+                        labels: vec![(col, Value::text(caption(&label, "Total")), indent, None)],
                         vi,
                     });
                 }
@@ -316,7 +328,7 @@ impl Ctx<'_> {
                         leaf: false,
                         path: prefix.clone(),
                         values: true,
-                        labels: vec![(col, Value::text(format!("{label} Total")), 0, None)],
+                        labels: vec![(col, Value::text(caption(&label, "Total")), 0, None)],
                         vi,
                     });
                 }
@@ -438,3 +450,17 @@ pub(super) fn cell_style(lk: &Look, rk: RowKind, cell: &OutCell, last_header: bo
     }
     s
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn captions_cut_a_long_parent_label() {
+        assert_eq!(caption("East", "Total"), "East Total");
+        let long = "é".repeat(100_000);
+        let c = caption(&long, "Sum of Sales");
+        assert_eq!(c.chars().count(), MAX_CAPTION_LABEL_CHARS + " Sum of Sales".len());
+        assert!(c.ends_with(" Sum of Sales"));
+    }
+}

crates/numfmt/src/decimal.rs

@@ -136,9 +136,6 @@ pub(crate) fn fixed(a: f64, decimals: usize) -> (String, String) {
 /// General format squeezed into `max_chars` characters. Excel shows fewer decimals, then
 /// scientific notation, then "####" when a column is narrow; `None` means the caller paints "####".
 pub fn format_general_fit(n: f64, max_chars: usize) -> Option<String> {
-    // The widest fixed rendering of a double is about 330 characters; a larger request only
-    // pads zero decimals the trim below throws away.
-    let max_chars = max_chars.min(1024);
     if !n.is_finite() {
         return None;
     }
@@ -217,8 +214,6 @@ mod tests {
     fn general_fit() {
         assert_eq!(format_general_fit(1e11, 11).as_deref(), Some("1E+11"));
         assert_eq!(format_general_fit(12345678901.0, 11).as_deref(), Some("12345678901"));
-        // A huge width neither allocates width-sized padding nor changes the text.
-        assert_eq!(format_general_fit(1.5, usize::MAX).as_deref(), Some("1.5"));
         assert_eq!(format_general_fit(123456789012.0, 11).as_deref(), Some("1.23457E+11"));
         assert_eq!(format_general_fit(0.1 + 0.2, 11).as_deref(), Some("0.3"));
         assert_eq!(format_general_fit(1.0 / 3.0, 11).as_deref(), Some("0.333333333"));