Ruby bindings for NimbleMarkets/ntcharts.
Render beautiful charts directly in your terminal. Built with TUIs in mind.
Add to your Gemfile:
gem "ntcharts"Or install directly:
gem install ntchartsCompact time-series visualization:
require "ntcharts"
chart = Ntcharts::Sparkline.new(40, 6)
[1, 4, 2, 7, 3, 9, 5, 8, 2, 6].each { |v| chart.push(v) }
chart.draw
puts chart.viewStyled sparkline with lipgloss:
require "lipgloss"
style = Lipgloss::Style.new.foreground("#FF6B6B")
chart = Ntcharts::Sparkline.new(40, 6)
chart.style = style # Accepts Lipgloss::Style or Ntcharts::Style
[5, 3, 7, 2, 9, 4, 6, 1, 8, 3].each { |v| chart.push(v) }
chart.draw_braille
puts chart.viewHorizontal and vertical bar charts:
chart = Ntcharts::Barchart.new(50, 12)
chart.push(label: "Go", values: [{ value: 85, style: style }])
chart.push(label: "Ruby", values: [{ value: 92, style: style }])
chart.push(label: "Python", values: [{ value: 78, style: style }])
puts chart.renderStacked bar segments:
chart.push(
label: "Sales",
values: [
{ value: 30, style: red_style },
{ value: 45, style: green_style },
{ value: 25, style: blue_style }
]
)X/Y coordinate plotting:
chart = Ntcharts::Linechart.new(50, 12, 0.0, 10.0, 0.0, 10.0)
(0..10).each do |i|
x = i.to_f
y = Math.sin(i * 0.5) * 4 + 5
chart.draw_rune(x, y, "*")
end
chart.draw_axes
puts chart.viewBraille lines for smooth curves:
chart = Ntcharts::Linechart.new(60, 15, 0.0, 30.0, -5.0, 10.0)
points = (0..30).map { |i| [i.to_f, Math.sin(i * 0.2) * 4 + 3] }
points.each_cons(2) do |(x1, y1), (x2, y2)|
chart.draw_braille_line(x1, y1, x2, y2)
end
chart.draw_axes
puts chart.viewThin lines (box-drawing characters)
chart.draw_line(0, 0, 10, 10, Ntcharts::Linechart::LINE_STYLE_THIN)Arc lines (curved connections)
chart.draw_line(0, 0, 10, 10, Ntcharts::Linechart::LINE_STYLE_ARC)Multiple named datasets:
chart = Ntcharts::Wavelinechart.new(60, 15)
(0..40).each { |i| chart.plot(i.to_f, Math.sin(i * 0.15) * 5 + 5) }
(0..40).each do |i|
chart.plot_data_set("series_a", i.to_f, Math.cos(i * 0.15) * 4 + 5)
chart.plot_data_set("series_b", i.to_f, Math.sin(i * 0.1) * 3 + 5)
end
chart.draw_all
puts chart.viewReal-time scrolling data:
chart = Ntcharts::Streamlinechart.new(60, 12)
chart.style = Lipgloss::Style.new.foreground("#00D4FF")
loop do
value = Math.sin(Time.now.to_f) * 4 + 5
chart.push(value)
system("clear")
puts chart.render
sleep 0.1
endTime-based X-axis with date labels:
chart = Ntcharts::Timeserieslinechart.new(70, 15)
now = Time.now
(0..60).each do |i|
time = now - (60 - i) * 60
value = Math.sin(i * 0.1) * 10 + 50
chart.push(time, value)
end
chart.draw_braille
puts chart.viewAll charts support lipgloss styling:
require "lipgloss"
chart_style = Lipgloss::Style.new.foreground("#FF6B6B")
axis_style = Lipgloss::Style.new.foreground("#666666")
label_style = Lipgloss::Style.new.foreground("#888888")
chart.style = chart_style
chart.axis_style = axis_style
chart.label_style = label_styleOr use Ntcharts::Style directly:
style = Ntcharts::Style.new
.foreground("#00FF00")
.background("#000033")
.bold(true)
chart.style = style| Chart | Description | Key Features |
|---|---|---|
Sparkline |
Compact time-series | Column and braille rendering modes |
Barchart |
Bar charts | Horizontal/vertical, stacked segments |
Linechart |
Base X/Y plotting | Points, lines, braille, custom runes |
Wavelinechart |
Multi-dataset lines | Named datasets, arc/thin line styles |
Streamlinechart |
Scrolling streams | Push data, auto-scroll right-to-left |
Timeserieslinechart |
Time-based charts | Ruby Time objects, date labels |
| Method | Description |
|---|---|
push(value) |
Add a data point |
draw |
Render with column characters |
draw_braille |
Render with braille dots |
view |
Get rendered string |
style= |
Set chart style |
max= |
Set maximum value |
auto_max_value= |
Enable/disable auto-scaling |
resize(width, height) |
Resize the chart |
clear |
Clear all data |
| Method | Description |
|---|---|
push(bar_data) |
Add a bar (Hash or BarData) |
push_all(array) |
Add multiple bars |
render |
Draw and return view |
horizontal= |
Set horizontal orientation |
bar_width= |
Set bar width |
bar_gap= |
Set gap between bars |
show_axis= |
Show/hide axis |
axis_style= |
Set axis style |
label_style= |
Set label style |
| Method | Description |
|---|---|
draw_rune(x, y, char, [style]) |
Draw character at point |
draw_line(x1, y1, x2, y2, line_style, [style]) |
Draw line segment |
draw_braille_line(x1, y1, x2, y2, [style]) |
Draw braille line |
draw_axes |
Draw X and Y axes |
view |
Get rendered string |
set_x_range(min, max) |
Set X data range |
set_y_range(min, max) |
Set Y data range |
x_step= / y_step= |
Set axis step (0 to hide) |
| Method | Description |
|---|---|
push(value) |
Add value (scrolls left) |
render |
Draw and return view |
set_y_range(min, max) |
Set Y range |
style= |
Set line style |
clear_data |
Clear data points |
| Method | Description |
|---|---|
push(time, value) |
Add time point |
push_data_set(name, time, value) |
Add to named dataset |
draw / draw_all |
Render default/all datasets |
draw_braille / draw_braille_all |
Braille rendering |
set_time_range(min, max) |
Set time range |
line_style= |
Set line style (THIN/ARC) |
Available on Linechart, Wavelinechart, Streamlinechart, Timeserieslinechart:
| Constant | Description |
|---|---|
LINE_STYLE_THIN |
Box-drawing characters |
LINE_STYLE_ARC |
Curved arc connections |
Requirements:
- Go 1.23+
- Ruby 3.2+
Install dependencies:
bundle installBuild the Go library and compile the extension:
bundle exec rake go:build
bundle exec rake compileRun demos:
./demo/sparkline
./demo/barchart
./demo/linechart
./demo/wavelinechart
./demo/streamlinechart
./demo/timeserieslinechart
./demo/streamingBug reports and pull requests are welcome on GitHub at https://github.com/marcoroth/ntcharts-ruby.
The gem is available as open source under the terms of the MIT License.
This gem wraps NimbleMarkets/ntcharts, which builds on the excellent Charm ecosystem including lipgloss. Charm Ruby is not affiliated with or endorsed by Charmbracelet, Inc.
Part of Charm Ruby.
Lipgloss • Bubble Tea • Bubbles • Glamour • Huh? • Harmonica • Bubblezone • Gum • ntcharts
The terminal doesn't have to be boring.