Tutorial 2: Multi-Panel Layout Principles

Goal

Understand layout principles and panel composition with EasyPlot:

• margins and relative positioning,

• createGridAxes and createAxesAgainstAxes,

• storing panels in 2D cell arrays,

• place / align / move.

Core functions

• EasyPlot.createGridAxes

• EasyPlot.createAxesAgainstAxes

• EasyPlot.place

• EasyPlot.align

• EasyPlot.move

Layout model

The figure below is useful for understanding how EasyPlot thinks about layout. The axes have their own Width and Height, but they also reserve MarginLeft, MarginRight, MarginTop, and MarginBottom. The figure itself has another set of margins. After EasyPlot.cropFigure(fig), the final canvas size is determined by the axes sizes plus all reserved margins.

Read this diagram as:

• axes Width and Height define the plotting area itself,

• axes margins define the extra space that belongs to labels, ticks, and titles,

• figure margins define the outer whitespace of the entire composition,

• cropping at the end converts those layout decisions into the final figure size.

Example

fig = EasyPlot.figure('Visible', 'off');

ax_grid = EasyPlot.createGridAxes(fig, 2, 3, ...
    'Width', 2.5, 'Height', 2.1, ...
    'MarginLeft', 0.55, 'MarginRight', 0.45, ...
    'MarginTop', 0.45, 'MarginBottom', 0.75, ...
    'FontSize', 7);

ax_side = EasyPlot.createAxesAgainstAxes(fig, ax_grid{1,3}, 'right', ...
    'Width', 1.7, 'Height', 2.1, 'YAxisVisible', 'off', 'FontSize', 7);

for r = 1:2
    for c = 1:3
        ax = ax_grid{r,c};
        x = linspace(0, 10, 200);
        plot(ax, x, sin(x + 0.4*(r-1) + 0.7*(c-1)), 'LineWidth', 1);
        title(ax, sprintf('R%dC%d', r, c), 'FontSize', 7);
    end
end

histogram(ax_side, randn(450,1), 20, ...
    'FaceColor', [0.35,0.35,0.35], 'EdgeColor', 'none');
title(ax_side, 'Side panel', 'FontSize', 7);

EasyPlot.align(ax_side, ax_grid{2,3}, 'bottom');
EasyPlot.place(ax_side, ax_grid{2,3}, 'right');
EasyPlot.move(ax_grid(:,2:3), 'dx', 0.25);

EasyPlot.cropFigure(fig);
EasyPlot.exportFigure(fig, fullfile('./docs/tutorials/_images', 'tutorial2_layout.png'));

Expected output

Layout tips

• Think in relationships (right-of, bottom-of, aligned-to) instead of absolute coordinates.

• Keep panels in cell arrays so batch operations stay simple and robust.

• Use margins to reserve space for labels and titles before you start moving panels around.

• Crop only at the end, after the layout is stable.

Next step

Continue with Tutorial 3: Multi-Axes Wrappers for Labels, Ticks, and Titles.