Multi-Plot Point Keyword Examples

This page demonstrates the new point keyword for the multi-plot directive.

Example 1: Using function evaluation with flattened index

In this example, point: (1, f(2)), 1 adds the point (1, f(2)) to axis 1 (first plot, top-left). The value f(2) is evaluated using the function f(x) = (x-1)² + 1.

Example 2: Using (row, col) format with function evaluation

In this example, point: (1, h(2)), (2, 1) adds the point (1, h(2)) to the axis at row 2, column 1 (third plot, bottom-left, function h).

Example 3: Multiple points with function evaluation

This example shows multiple point entries targeting different axes, each evaluating their respective functions.

Example 4: Combining with legacy points keyword

You can mix the legacy points keyword (per-axis lists) with the new point keyword (axis-targeted).

Example 5: Numeric coordinates (no function calls)

The point keyword also works with plain numeric coordinates.

HLine Examples

Example 6: Basic horizontal line

Full-width horizontal lines at y=2 on axis 1 and y=-1 on axis 3.

Example 7: Horizontal line with x-extent

Horizontal lines with specified x-ranges: from x=-2 to x=2 at y=1 on axis 1, and from x=0 to x=3 at y=g(1) on row 1, col 2.

Example 8: Combining point and hline

You can combine point and hline keywords to mark both points and reference lines on specific axes.

VLine Examples

Example 9: Basic vertical line

Full-height vertical lines at x=1 on axis 1 and x=-2 on axis 3.

Example 10: Vertical line with y-extent

Vertical lines with specified y-ranges: from y=-2 to y=2 at x=1 on axis 1, and from y=0 to y=3 at x=sqrt(2) on row 1, col 2.

Example 11: Combining point, hline, and vline

You can combine point, hline, and vline keywords to create comprehensive reference markers on specific axes.

Using the line keyword

The line keyword allows you to add reference lines with axis targeting. It supports two forms:

• Slope-intercept: line: a, b, axis_spec for y = a*x + b

• Point-slope: line: a, (x0, y0), axis_spec for a line with slope a through point (x0, y0)

Example 12: Basic line with slope-intercept form

Adds y = 2x + 1 on axis 1 and y = -x + 2 on axis 3.

Example 13: Line with point-slope form

Adds line with slope 2 through (1, 3) on axis 1, and slope -1 through (0, 2) on row 2, col 1.

Example 14: Line with function evaluation

Adds secant line through (1, f(1)) and (4, f(4)) using computed slope on axis 1.

Example 15: Combining all reference markers

You can combine point, hline, vline, and line keywords for comprehensive visualization.

Using the tangent keyword

The tangent keyword allows you to add tangent lines to functions at specified points. The derivative is computed automatically using SymPy.

Example 16: Basic tangent line

Adds tangent to f at x=2 on axis 1, and tangent to g at x=-1 on axis 2.

Example 17: Tangent with (row, col) addressing

Tangent lines on row 1 col 1 (f at x=1), row 1 col 2 (g at x=π/2), and row 2 col 1 (h at x=0).

Example 18: Tangent with point marker

Combines tangent lines with point markers at the points of tangency.

Example 19: Multiple tangents on same axis

Multiple tangent lines can be added to the same axis. This example shows two tangents to f(x) = x³ - 4x at x=-1 and x=1.

Using per-axis limits

The xmin, xmax, ymin, and ymax keywords allow you to set axis limits either globally or per-axis.

Example 20: Per-axis limits with axis targeting

Sets custom x and y limits for axis 1 (x from -5 to 5, y from 0 to default), and custom x limits for axis 2 (x from -2π to 2π).

Example 21: Global limits applied to all axes

Sets the same limits for all axes: x from -3 to 3, y from -5 to 5.

Example 22: Mixing global and per-axis limits

Sets global x limits (-5 to 5) for all axes, custom ymax for axis 3, and custom y range for axis at row 2, col 1.