ImPlot: 2D plots for Dear ImGui: lines, scatter, bars, shaded areas, heatmaps, histograms, pie charts, real-time data.
A plot lives between begin_plot() and end_plot(): the setup_* functions (axes, limits, legend) come first,
then the plot_* functions. Run the app with immapp.run(..., with_implot=True), which creates ImPlot’s context.
In Python, the data are numpy arrays. ImPlot’s functions are templated on one numeric type, so the arrays of one
call must share their dtype: convert them first (xs = xs.astype(ys.dtype)). Mismatched dtypes raise an error.
Upstream repository · The book’s page
Modules¶
In imgui_bundle (from imgui_bundle import implot):
implot: 125 functions, 8 classes, 36 enums · the C++ viewimplot.internal: 91 functions, 21 classes, 4 enums · the C++ view
Demos using it¶
The demos of the catalog that use it (the pictures link to their code and to the playground).
A parametric curve¶
Turn the knobs, or click Random: the curve follows at once.
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At every frame, the GUI function draws the plot with ImPlot and the knobs with imgui-knobs, and reads their values right there. No callbacks, no widget objects: that is the immediate mode.
Uses: ImPlot, knobs
Assets and add-ons¶
Load images and icons from your assets folder, and use two add-ons: markdown and ImPlot.
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A markdown editor with a live preview, and a pie chart whose values you can drag. Tick More info under each part to see how it is done. The add-ons are activated with immapp.AddOnsParams.
Uses: ImPlot
A tiny neural network learns two spirals¶
Can 16 neurons tell two spirals apart? Watch a tiny neural network learn, live, as in the TensorFlow Playground.
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Then read how it works, formula by formula, next to its numpy code.
Uses: ImPlot
Simple harmonic motion¶
A mass on a spring, a pendulum, a vibrating string: they all follow the same equation.
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It is the equation of simple harmonic motion (for the pendulum, at small angles). Adjust the mass and the spring stiffness, and watch how the motion changes.
Uses: ImPlot, knobs
Double pendulum¶
A double pendulum is a chaotic system: tiny changes in its initial conditions lead to wildly different trajectories.
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Drag the angles to set initial positions, then release and watch chaos unfold.
Uses: ImPlot, knobs, toggles
Fourier epicycles¶
Any closed curve can be approximated by a sum of rotating circles (a Fourier series).
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Adjust the number of circles to see how the approximation improves.
Uses: ImPlot, knobs, toggles
Logistic map¶
A very simple equation, and yet it can lead to wildly different behaviors, up to chaos.
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The logistic map, x(n+1) = r * x(n) * (1 - x(n)), models for example the growth of a population with limited resources. Depending on r, it is stable, periodic (in 2-cycles, 4-cycles, etc), or chaotic. Let’s explore this.
Uses: ImPlot, toggles
Node editor: an image pipeline¶
An image flows through a graph of filters, and each node shows its result.
More
Change a parameter, and the nodes downstream follow at once. The patterns of imgui-node-editor for a real app: typed pins, links refused with a reason, a node created by dropping a link in empty space, menus, a group.
Uses: ImPlot, ImmVision, node editor, OpenCV
ImPlot: the interactive manual¶
Every kind of plot of ImPlot, section by section, with the code of each beside it.
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Lines, scatter, bars, heatmaps, histograms, real-time plots and more, in Python and C++. From Dear ImGui Explorer, the interactive manual for Dear ImGui and its libraries.
Uses: ImPlot
Context managers (imgui_ctx)¶
In Python, with imgui_ctx.begin("Window"): replaces a begin() / end() pair, and the end() can no longer be forgotten.
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The same exists for child windows, menus, popups, tables, tabs, fonts and styles, and for ImPlot with implot_ctx. Open a section to try it and read its code. See the Python tips.
Uses: ImPlot