PlotFunction — Analysis Tool Box

Introduction

Before you trust a model or a derived quantity, it helps to see how it behaves — where it rises, flattens, peaks, or breaks down — rather than reason about it purely from an equation. PlotFunction answers "what does this relationship actually look like across its input range?" by rendering any callable as a clean, presentation-ready line plot over a chosen interval. Reach for it when you need to expose non-linear features — plateaus, inflection regions, thresholds — that raw numbers or a symbolic expression alone can obscure, whether you're validating a model or communicating its shape to a non-technical audience.

Teaching Note

Plotting a function reveals qualitative features — curvature, growth rate changes, local maxima/minima, and boundaries — in ways that raw numerical output cannot. Visual inspection remains a cornerstone of analytic sense-making across disciplines.

Parameters

Parameter	Type	Default	Description
`f_of_x`required		—	The function of x to plot.
`minimum_x`	`int`	`-10`	The minimum value of x to use when plotting the function.
`maximum_x`	`int`	`10`	The maximum value of x to use when plotting the function.
`n`	`int`	`100`	The number of points to use when plotting the function.
`line_color`	`str`	`'#3269a8'`	The color of the function plot line.
`line_alpha`	`float`	`0.8`	The alpha (transparency) of the function plot line.
`markers`	`str`	`'o'`	The marker style to use for the function plot.
`x_axis_variable_name`	`str`	`'x'`	The label for the x-axis.
`y_axis_variable_name`	`str`	`'f(x)'`	The label for the y-axis.
`title_for_plot`	`str`	`'Function Plot'`	The title for the plot.
`subtitle_for_plot`	`str`	`'Shows the function of x'`	The subtitle for the plot.
`caption_for_plot`	`str`	`None`	The caption for the plot.
`data_source_for_plot`	`str`	`None`	The data source for the plot.
`x_indent`	`float`	`-0.127`	The x-indent for the x-axis label.
`title_y_indent`	`float`	`1.125`	The y-indent for the title.
`subtitle_y_indent`	`float`	`1.05`	The y-indent for the subtitle.
`caption_y_indent`	`float`	`-0.3`	The y-indent for the caption.
`figure_size`	`tuple`	`(8, 5)`	The size of the plot figure.

Returns

None — the function displays a plot.

Example

python

from analysistoolbox.calculus import PlotFunction

# Plot f(x) = x^2 over the default range
PlotFunction(
    f_of_x=lambda x: x**2,
    minimum_x=-10,
    maximum_x=10,
    title_for_plot="Function Plot",
    subtitle_for_plot="Shows the function of x",
)