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ggterm-plot

Create terminal data visualizations using Grammar of Graphics. Use when plotting data, creating charts, graphing, visualizing distributions, or when the user mentions plot, chart, graph, histogram, scatter, boxplot, or visualize.

SKILL.md

Full skill instructions

Terminal Plotting with ggterm

Create plots using the CLI tool. Start by inspecting the data, then plot.

Step 1: Inspect Data (Recommended)

bun packages/​core/​src/​cli-plot.ts inspect <data.csv>

Shows column names, types (numeric/​categorical/​date), unique counts, and sample values.

Step 2: Get Suggestions (Optional)

bun packages/​core/​src/​cli-plot.ts suggest <data.csv>

Returns ready-to-run plot commands based on column types.

Step 3: Create Plot

bun packages/​core/​src/​cli-plot.ts <data.csv> <x> <y> [color] [title] [geom]

Arguments:

  • data.csv - Path to CSV file (use absolute path or relative to ggterm dir)
  • x - Column name for x-axis
  • y - Column name for y-axis (use - for histogram)
  • color - Column name for color (optional, use - to skip)
  • title - Plot title (optional, use - to skip)
  • geom - Geometry type: point (default), line, path, step, bar, col, histogram, freqpoly, density, boxplot, violin, ridgeline, joy, beeswarm, quasirandom, dumbbell, lollipop, waffle, sparkline, bullet, braille, calendar, flame, icicle, corrmat, sankey, treemap, area, ribbon, rug, errorbar, errorbarh, crossbar, linerange, pointrange, smooth, segment, curve, rect, tile, raster, bin2d, text, label, contour, contour_filled, density_2d, qq, qq_line, hline, vline, abline

Examples

Scatter plot:

bun packages/​core/​src/​cli-plot.ts data/​iris.csv sepal_length sepal_width species "Iris Dataset" point

Line chart:

bun packages/​core/​src/​cli-plot.ts data/​stocks.csv date price symbol "Stock Prices" line

Histogram:

bun packages/​core/​src/​cli-plot.ts data/​iris.csv sepal_width - - "Sepal Width Distribution" histogram

Box plot:

bun packages/​core/​src/​cli-plot.ts data/​experiment.csv treatment response_time - "Response by Treatment" boxplot

Workflow

  1. Identify the data file from $ARGUMENTS or ask user
  2. Run inspect to see column names and types
  3. Run suggest to get recommended visualizations (or choose based on user request)
  4. Run the plot command
  5. Briefly describe what the plot shows

$ARGUMENTS

Geom Selection Guide

Data QuestionGeomExample
Relationship between 2 variablesgeom_point()Scatter plot
Trend over timegeom_line()Time series
Distribution of 1 variablegeom_histogram()Frequency distribution
Smoothed distributiongeom_density()Kernel density estimate
Distribution by groupgeom_boxplot()Compare medians
Density shapegeom_violin()Distribution shape
Stacked distributionsgeom_ridgeline()Joy plot / ridgeline
Individual pointsgeom_beeswarm()Avoid overlap in groups
Before/​after comparisongeom_dumbbell()Two connected points
Sparse rankingsgeom_lollipop()Clean bar alternative
Part-of-wholegeom_waffle()Grid-based pie alternative
Inline trendsgeom_sparkline()Word-sized charts
KPI progressgeom_bullet()Progress with target
High resolutiongeom_braille()8x detail using braille
Activity over timegeom_calendar()GitHub-style heatmap
Performance profilinggeom_flame()Call stack visualization
Variable correlationsgeom_corrmat()Correlation matrix
Flow between categoriesgeom_sankey()Source to target flows
Hierarchical proportionsgeom_treemap()Nested rectangles by value
Category comparisongeom_bar()Counts per category
Known values per categorygeom_col()Bar heights from data
Trend with uncertaintygeom_smooth()Fitted line
2D densitygeom_density_2d()Contour density
Filled regiongeom_area()Cumulative or stacked
Error rangesgeom_errorbar()Confidence intervals
Normality checkgeom_qq()Q-Q plot
Multi-distribution comparisongeom_freqpoly()Overlaid frequency lines

Common Plot Types

Scatter Plot

gg(data)
  .aes({ x: 'weight', y: 'height', color: 'species' })
  .geom(geom_point({ size: 2 }))

Line Chart

gg(data)
  .aes({ x: 'date', y: 'value', color: 'category' })
  .geom(geom_line())

Histogram

import { geom_histogram } from '@ggterm/​core'

gg(data)
  .aes({ x: 'value' })
  .geom(geom_histogram({ bins: 20 }))

Box Plot

import { geom_boxplot } from '@ggterm/​core'

gg(data)
  .aes({ x: 'group', y: 'value' })
  .geom(geom_boxplot())

Bar Chart

import { geom_bar } from '@ggterm/​core'

gg(data)
  .aes({ x: 'category', fill: 'category' })
  .geom(geom_bar())  // Counts occurrences

Color and Styling

Color Scales

import { scale_color_viridis, scale_color_brewer } from '@ggterm/​core'

// Viridis (perceptually uniform)
gg(data)
  .aes({ x: 'x', y: 'y', color: 'value' })
  .geom(geom_point())
  .scale(scale_color_viridis())

// ColorBrewer palettes
.scale(scale_color_brewer({ palette: 'Set1' }))  // Categorical
.scale(scale_color_brewer({ palette: 'Blues' })) // Sequential

Themes

import { themeDark, themeMinimal, themeClassic } from '@ggterm/​core'

gg(data)
  .aes({ x: 'x', y: 'y' })
  .geom(geom_point())
  .theme(themeDark())      // Dark background
  // or .theme(themeMinimal())  // Clean, minimal
  // or .theme(themeClassic())  // Traditional

Faceting (Small Multiples)

import { facet_wrap, facet_grid } from '@ggterm/​core'

// Wrap into grid
gg(data)
  .aes({ x: 'x', y: 'y' })
  .geom(geom_point())
  .facet(facet_wrap({ vars: 'category', ncol: 3 }))

// Grid by two variables
.facet(facet_grid({ rows: 'year', cols: 'region' }))

Scale Transformations

import { scale_x_log10, scale_y_sqrt } from '@ggterm/​core'

gg(data)
  .aes({ x: 'population', y: 'gdp' })
  .geom(geom_point())
  .scale(scale_x_log10())
  .scale(scale_y_sqrt())

Layering Multiple Geoms

gg(data)
  .aes({ x: 'time', y: 'value' })
  .geom(geom_point({ alpha: 0.5 }))  // Points first
  .geom(geom_line())                  // Line on top
  .geom(geom_smooth({ method: 'loess' }))  // Trend line

Annotations

import { annotate_text, annotate_hline, annotate_rect } from '@ggterm/​core'

gg(data)
  .aes({ x: 'x', y: 'y' })
  .geom(geom_point())
  .annotate(annotate_hline({ yintercept: 0, linetype: 'dashed' }))
  .annotate(annotate_text({ x: 10, y: 5, label: 'Important point' }))

Saving Plot Specifications

For reproducibility, save the PlotSpec alongside output:

import { writeFileSync } from 'fs'

const plot = gg(data).aes({ x: 'x', y: 'y' }).geom(geom_point())

// Get JSON-serializable specification
const spec = plot.spec()
writeFileSync('plot-spec.json', JSON.stringify(spec, null, 2))

// Render to terminal
console.log(plot.render({ width: 80, height: 24 }))

Render Options

plot.render({
  width: 80,           // Characters wide
  height: 24,          // Lines tall
  renderer: 'auto',    // 'braille' | 'block' | 'sixel' | 'auto'
  colorMode: 'truecolor'  // Use 'truecolor' for full color support
})

Quick Reference

For detailed examples, see examples/​basic-plots.md.

All Available Geoms (52 total)

Point/​line: geom_point, geom_line, geom_path, geom_step Bar: geom_bar, geom_col, geom_histogram, geom_freqpoly, geom_density Distribution: geom_boxplot, geom_violin, geom_ridgeline, geom_joy, geom_beeswarm, geom_quasirandom, geom_density_2d, geom_qq, geom_qq_line Comparison: geom_dumbbell, geom_lollipop Terminal-native: geom_waffle, geom_sparkline, geom_bullet, geom_braille Specialized: geom_calendar, geom_flame, geom_icicle, geom_corrmat, geom_sankey, geom_treemap Area: geom_area, geom_ribbon Reference: geom_hline, geom_vline, geom_abline, geom_segment, geom_curve Text: geom_text, geom_label Error bars: geom_errorbar, geom_errorbarh, geom_crossbar, geom_linerange, geom_pointrange 2D/​Tile: geom_tile, geom_raster, geom_bin2d, geom_rect, geom_contour, geom_contour_filled Other: geom_rug, geom_smooth

All Available Scales

Position: scale_x_continuous, scale_y_continuous, scale_x_log10, scale_y_log10, scale_x_sqrt, scale_y_sqrt, scale_x_reverse, scale_y_reverse, scale_x_discrete, scale_y_discrete

Color: scale_color_continuous, scale_color_discrete, scale_color_viridis, scale_color_brewer, scale_color_gradient, scale_color_gradient2, scale_fill_* (same variants)

Size: scale_size_continuous, scale_size_area, scale_size_radius

DateTime: scale_x_datetime, scale_y_datetime, scale_x_date, scale_y_date