Subplots

In rallyplot, a ‘subplot’ is a separate graph with independent x- and y-axis to all other existing plots. This is in contrast to a linked-subplot, in which the x-axis are shared between plots.

A new subplot can be created with the add_subplot() (Python) / addSubplot() (C++) function. This function takes 4 arguments:

• row: The row (zero-indexed) position in the window where the subplot will be placed

• column: The zero-indexed column position in the window where the subplot will be placed

• row stretch: The number of rows the subplot spans

• column stretch: The number of columns the subplot spans

The most recently added subplot becomes the active subplot. All subsequent plotting and setting function calls will apply to that subplot only. When adding a new subplot, existing settings will be applied to the new subplot. To go back and edit a subplot, use set_active_subplot(row, col) (Python) / setActiveSubplot(row, col) (C++). See the example scripts below for practical demonstrations of these features.

Python

from rallyplot import Plotter
from rallyplot.plotter import get_toy_candlestick_data

plotter = Plotter(anti_aliasing_samples=8)

open_high_low_close_df, volume, dates = get_toy_candlestick_data(N=100_000)

# Plot a candlestick chart
plotter.candlestick_from_df(
    open_high_low_close_df, dates
)

# add a linked subplot and plot onto it
plotter.add_linked_subplot(0.33)

y = open_high_low_close_df["open"].to_numpy()

plotter.line(y)

plotter.set_legend(["Subplot Data 1.1"], linked_subplot_idx=0)
plotter.set_legend(["Subplot Data 1.2"], linked_subplot_idx=1)

# Now, add a new subplot. This will be positioned to the
# right of the original subplot. As soon as we add a new
# subplot it becomes the 'active' subplot, and all 'plotter'
# calls affect that subplot
plotter.add_subplot(0, 1, 1, 1)

plotter.line(volume, color=(0.25, 0.22, 0.66), width=1.0)

plotter.set_legend(["Subplot Data 2"])

# We can change settings on this subplot. These settings will
# be remembered and used for all future subplots.
plotter.set_crosshair_settings(on=False)

# Add another subplot, underneath the two existing subplots.
# Set the stretch to '2' to span the entire width of the window.
plotter.add_subplot(1, 0, 1, 2)

plotter.candlestick_from_df(open_high_low_close_df, dates)


# We can add a linked subplot to a subplot as usual.
plotter.add_linked_subplot(0.33)

plotter.bar(volume)

plotter.set_legend(["Subplot Data 3.1"], linked_subplot_idx=0)
plotter.set_legend(["Subplot Data 3.2"], linked_subplot_idx=1)

# We can set the active subplot to operate on
# particular subplots as desired
for idx in ((0, 0), (0, 1), (1, 0)):
    plotter.set_active_subplot(*idx)
    plotter.set_title("My Plot Title")
    plotter.set_x_label("My X Label")
    plotter.set_y_label("My Y  Label")
    plotter.set_hover_value_settings(display_mode="off")


plotter.start()

C++

#include <Plotter.h>
#include <ToyData.h>
#include <vector>

int main(int argc, char* argv[])
{
    PlotterArgs plotterArgs{};
    plotterArgs.antiAliasingSamples = 8;

    Plotter plotter = Plotter();

    CandleData candleData = getToyCandlestickData(100000);

    // Plot a candlestick chart
    plotter.candlestick(
        candleData.open,
        candleData.high,
        candleData.low,
        candleData.close,
        candleData.dates
        );

    // add a linked subplot and plot onto it
    plotter.addLinkedSubplot(0.33);

    const std::vector<float>& y = candleData.open;

    plotter.line(y);

    // The second argument, linkedSubplotIdx, specified
    // the linekd subplot to set the legend on
    plotter.setLegend({"Subplot Data 1.1"}, std::nullopt, 0);
    plotter.setLegend({"Subplot Data 1.2"}, std::nullopt, 1);

    // Now, add a new subplot. This will be positioned to the
    // right of the original subplot. As soon as we add a new
    // subplot it becomes the 'active' subplot, and all 'plotter'
    // calls affect that subplot
    plotter.addSubplot(0, 1, 1, 1);

    LineSettings lineSettings{};
    lineSettings.color = {0.25, 0.22, 0.66};
    lineSettings.width = 1.0f;
    plotter.line(candleData.volume, lineSettings);

    plotter.setLegend({"Subplot Data 2"});

    // We can change settings on this subplot. These settings will
    // be remembered and used for all future subplots.
    CrosshairSettings crosshairSettings;
    crosshairSettings.on = false;
    plotter.setCrosshairSettings(crosshairSettings);

    // Add another subplot, underneath the two existing subplots.
    // Set the stretch to '2' to span the entire width of the window.
    plotter.addSubplot(1, 0, 1, 2);


    // Plot a candlestick chart
    plotter.candlestick(
        candleData.open,
        candleData.high,
        candleData.low,
        candleData.close,
        candleData.dates
        );

    // We can add a linked subplot to a subplot as usual.
    plotter.addLinkedSubplot(0.33);

    plotter.bar(candleData.volume);

    plotter.setLegend({"Subplot Data 3.1"}, std::nullopt, 0);
    plotter.setLegend({"Subplot Data 3.2"}, std::nullopt, 1);

    // We can set the active subplot to operate on
    // particular subplots as desired

    HoverValueSettings hoverValueSettings{};
    hoverValueSettings.displayMode = HoverValueDisplayMode::off;

    for (std::pair<int,int> idx : std::initializer_list<std::pair<int,int>>{{0, 0}, {0, 1}, {1, 0}})
    {
        plotter.setActiveSubplot(idx.first, idx.second);
        plotter.setTitle("My Plot Title");
        plotter.setXLabel("My X Label");
        plotter.setYLabel("My Y  Label");
        plotter.setHoverValueSettings(hoverValueSettings);
    }

    plotter.start();
}