Quadrant Chart

Draw labelled quadrant charts in Obsidian, with free-floating text placed anywhere on the plot. Charts live in .mdx files as plain YAML frontmatter, so they stay readable, hand-editable, and diff-friendly.

What it does

• Any N × M grid, not just four quadrants. Set columns and rows independently, from 1×1 to 12×12.
• Labelled axes — name the X and Y axes, set their ranges, and the tick values are derived. Explicit ticks are supported when you want them.
• Axis notes — a line of smaller muted text beside an axis, saying what the scale actually is: where the numbers came from, whether higher is better. Written into the .mdx, so it travels with the chart and can be generated by a script.
• Free text anywhere — labels are not tied to quadrants. Drop one at any coordinate, drag it to reposition, double-click to edit, right-click to delete. Long ones wrap at a width you choose.
• Cell labels, notes and colours — name each cell, add longer text underneath, and tint it.
• Styled labels — give a label its own background plate, an outline, and its own text size, so it stays readable wherever it lands.
• Overlapping labels are reachable — click the same spot again to step down through the stack, or use Bring to front / Send to back.
• Undo and redo — Ctrl+Z and Ctrl+Shift+Z step through any change, including an accidental drag.
• Export — save the chart as a JPG or PNG next to the .mdx file.
• Built-in examples — a SWOT and a talent nine-box, creatable from the command palette.
• Your notes stay yours — the chart is the YAML frontmatter; everything below it is free text the plugin never touches.
• Scriptable — a chart is plain YAML, so anything that can write YAML can create one.

Using it

Create a chart — command palette → Create a blank chart. Pick a name and it opens straight into the editor.

Start from an example — command palette → Create from a worked example → SWOT or talent nine-box. You get the cells, colours, labels and an explanatory body to edit.

Add text — double-click anywhere on the plot, or use the Add label button. With nothing pointed at, a new label lands in the middle of the cell you last clicked. A label wider than the configured share of the plot (80% by default, see Maximum label width in the settings) wraps onto another line.

Move text — drag it.

Edit text — double-click it, or select it and use the Label button → Edit text…. Clearing the text deletes the label.

Delete text — right-click it, or select it and use the Label button → Delete label.

Select a label or a cell — click it. A click on a label selects the label, never the cell underneath; a click on empty space selects the cell. Both draw a dashed box.

Style a label — select it, then Label → background colour, Draw a box around it, or a text size. Default clears the size override so the label follows the chart again.

Reach a label under another — click the same spot repeatedly to step down the stack, or use Send to back / Bring to front. Order is stored in the file, so it survives a reload.

Name a cell — click the cell, then the Cell button.

Change the grid — the Grid N×M button. Columns and rows are independent, and the button always shows the current size. You can also drag a dashed split line on the canvas.

Name the axes / set the range — Axes button, or click the X or Y caption on the canvas.

Add an axis note — Axes → Note under the X axis… / Note beside the Y axis…. The X note is drawn below its caption and the Y note up the left gutter, each in smaller muted text; writing one reserves room for it, and clearing it gives the room back. A cell note says what is in a cell — an axis note says what the whole scale means, which is the one thing a quadrant chart cannot leave implicit.

Export an image — the Export button, or the command palette → Export as an image.

The file is written beside the .mdx and never overwrites an existing one.

Everything you do is written straight to the file, so you can also just edit the YAML.

Limits

A label is a label, not a paragraph. Free text wraps, but only at the configured width — see Maximum label width in the settings, 80% of the plot area by default. A 91-character Chinese label at the default 14px needs 1180px, so it wraps onto two lines. Push past a few hundred characters and you get a tall stack of lines rather than a readable block.

Two things follow:

• Keep a label to a phrase or a short sentence. That is what the format is for.
• When you need a paragraph, put it in the cell's note. Cell labels and notes wrap to the cell width, which is the right measure for a block of text, on screen and in every export format.

One halo colour per line. The outline that keeps a label readable where it crosses a grid line is coloured to match the cell that line sits in, so it is invisible against its own background. A label that overhangs a differently tinted cell still shows the ring on the overhanging part.

No multi-select. One label at a time — no marquee, no group operations.

Keyboard

A new change after an undo discards the redo branch, so redo can only replay something you have not since replaced.

The .mdx format

A chart is a YAML frontmatter block. The body after it is yours and is never modified.

---
quadrant-chart: 1
title: Q1 Priorities
x:
  label: Impact
  min: 0
  max: 10
y:
  label: Urgency
  min: 0
  max: 10
grid:
  columns: 2
  rows: 2
cells:
  - col: 1
    row: 1
    label: Do now
    color: "#d93025"
    note: Anything blocking a release
items:
  - id: a1
    text: Rework the sync engine
    x: 8.2
    y: 9
    background: "#fdd663"   # optional plate behind the text
    box: true                # optional outline around it
---

Notes go here. The plugin never rewrites anything below the frontmatter.

Coordinates are stored in data space — the axis min/max range — not in pixels. Resizing the pane or changing the range never rewrites your numbers, which is what lets a chart saved on a phone land in the same logical spot on a desktop.

quadrant-chart: 1 is what marks the file as a chart. Without it, a .mdx file is left alone.

A damaged file still opens: missing fields fall back to defaults, a reversed axis range is repaired, and out-of-range cells are dropped. The point is that you can always see the file to fix it.

One trap worth writing down, because it is not visible from the format:

row 0 is the bottom band. Rows are counted along Y from the minimum, and columns along X from the minimum. Get it backwards and a SWOT silently swaps "helpful" with "harmful" — the chart still renders, it is just wrong. The same applies to a nine-box, where it inverts high and low potential.

Generating charts programmatically

Because a chart is plain YAML, you do not need the plugin to create one. Anything that can write YAML can produce a chart; the plugin only has to render it. That includes an LLM, a cron job, a spreadsheet export, or another plugin.

A reference implementation ships with this workspace:

python3 /home/wang/wk/Script/mdx_chart.py --help

import sys; sys.path.insert(0, "/home/wang/wk/Script")
from mdx_chart import Chart, Axis

chart = Chart(
    title="SWOT",
    x=Axis("Internal  ———  External", -5, 5),
    y=Axis("Harmful  ———  Helpful", -5, 5),
    columns=2, rows=2,
)
chart.add_cell(0, 1, "Strengths",     color="green",  note="Internal · helpful")
chart.add_cell(0, 0, "Weaknesses",    color="red",    note="Internal · harmful")
chart.add_cell(1, 1, "Opportunities", color="blue",   note="External · helpful")
chart.add_cell(1, 0, "Threats",       color="orange", note="External · harmful")
chart.add_item("Plain-text format — git-diffable", x=-3.4, y=4.2, item_id="s1")
chart.save("SWOT.mdx", body="# Notes\n\nThis body is never rewritten.\n")

The same operations from the command line:

python3 Script/mdx_chart.py create   --path Q1.mdx --title "Q1 Priorities" --columns 2 --rows 2
python3 Script/mdx_chart.py set-cell --path Q1.mdx --col 1 --row 1 --label "Do now" --color red
python3 Script/mdx_chart.py add-item --path Q1.mdx --text "Rework sync engine" --x 8.2 --y 9
python3 Script/mdx_chart.py show     --path Q1.mdx        # JSON, for an agent to read

It edits in place: load() returns the chart and the body, and save() rewrites only the frontmatter, so notes written under a chart survive. It refuses to overwrite on create without --force, and refuses to touch a file that is not a chart at all.

Full reference — docs/API.md. It is written to be read by an agent: the field table, the complete API surface, the CLI, worked recipes for SWOT and the talent nine-box, the colour palette, a pre-write checklist, and the processFrontMatter warning below.

Worked examples, both generated through that API:

• /home/wang/wk/wk/SWOT-插件价值.mdx
• /home/wang/wk/wk/人才九宫格-示例.mdx

If you write a plugin that edits .mdx

Use app.vault.process(file, fn) for the atomic read-modify-write.

Do not use fileManager.processFrontMatter on a .mdx file. Measured on a live vault, it resolves successfully and writes nothing — the file stays byte-identical. It is a silent no-op, which is why it cost several rounds to track down. Its callback also takes (frontmatter) => void, so a returned object is discarded.

Note on the extension

.mdx is also React's component-file suffix. There is no conflict inside Obsidian, which has no MDX pipeline of its own, but be aware of it if a vault ever gains a real MDX toolchain.

Building

npm install
npm run build     # typecheck + production bundle -> main.js
npm test          # 377 tests: format, geometry, hit-testing, undo, image export, the
                  # save path, and interoperability with Script/mdx_chart.py

To build straight into a vault's plugin folder:

OUTDIR=~/vault/.obsidian/plugins/quadrant-chart npm run build