Titles and Labels

Each argument, if it is not None, is shown (using
`show_title()`, `show_xlabel()`, or `show_ylabel()`) and its
`visible` flag is set False to stop any later attempts to
re-show it.

If the `text` argument is None, then the current `self.title`
attribute is used instead.  If the flag `self.title_visible`
is True and the text is not None, then calls `show_text()`
with the text and the attributes controlling the appearance of
the title (`self.title_scale`, `self.title_shift`, etc.).

If the `text` argument is None, then the current `self.xlabel`
attribute is used instead.  If the flag `self.xlabel_visible`
is True and the text is not None, then calls `show_text()`
with the text and the attributes controlling the appearance of
the x label (`self.xlabel_position`, `self.xlabel_scale`,
etc.).

If the `text` argument is None, then the current `self.ylabel`
attribute is used instead.  If the flag `self.ylabel_visible`
is True and the text is not None, then calls `show_text()`
with the text and the attributes controlling the appearance of
the y label (`self.ylabel_position`, `self.ylabel_scale`,
etc.).

Defines the alignment for the title.  (Default: AlignedAtBaseline)

The angle of the baseline for the title with respect to the
side of the frame.  (Default: 0)

If not None, then is used to add a TeX "\textcolor"
specification to the title text.

Defines the justification for the title.  (Default: Centered)

The fractional position along the edge of the frame for the
title reference point.  The default `self.title_position` is
0.5 with `self.title_justification` = Centered.

Defines the text size scale for the title.  (Default: 1.1)

Defines the shift distance away from the frame edge for the
reference point of the title measured in units of text
heights.  (Default: 0.7)

The side of the frame for the title.  (Default: Top)

If True, then it is okay for tioga to show the title of a
plot.  If False, then calls on `show_title()` return
immediately.  This attribute is "one-way-only" in that it starts
True and can be set False, but cannot be reset to True except
by restoring the graphics state in which is was still True.
This is intended to help control the behavior of plots when
embedded as subplots in a larger configuration.  Note that
this does not effect calls on `show_text()`; it only applies
to calls on `show_title()`.

Defines the alignment for the x label.  (Default: AlignedAtBaseline)

The angle of the baseline for the x label with respect to the
side of the frame.  (Default: 0)

If not None, then is used to add a TeX "\textcolor"
specification to the x label text.

Defines the justification for the x label.  (Default: Centered)

The fractional position along the edge of the frame for the x
label reference point.  The default `self.xlabel_position` is
0.5 with `self.xlabel_justification` = Centered.

Defines the text size scale for the x label.  (Default: 1.0)

Defines the shift distance away from the frame edge for the
reference point of the x label measured in units of text
heights.  (Default: 1.0)

The side of the frame for the x label.  (Default: Bottom)

If True, then it is okay for tioga to show the x label of a
plot.  If False, then calls on `show_xlabel()` return
immediately.  This attribute is "one-way-only" in that it starts
True and can be set False, but cannot be reset to True except
by restoring the graphics state in which is was still True.
This is intended to help control the behavior of plots when
embedded as subplots in a larger configuration.  Note that
this does not effect calls on `show_text()`; it only applies
to calls on `show_xlabel()`.

Defines the alignment for the y label.  (Default: AlignedAtBaseline)

The angle of the baseline for the y label with respect to the
side of the frame.  (Default: 0)

If not None, then is used to add a TeX "\textcolor"
specification to the y label text.

Defines the justification for the y label.  (Default: Centered)

The fractional position along the edge of the frame for the y
label reference point.  The default `self.ylabel_position` is
0.5 with `self.ylabel_justification` = Centered.

Defines the text size scale for the y label.  (Default: 1.0)

Defines the shift distance away from the frame edge for the
reference point of the y label measured in units of text
heights.  (Default: 1.8)

The side of the frame for the y label.  (Default is Left)

If True, then it is okay for tioga to show the y label of a
plot.  If False, then calls on `show_ylabel()` return
immediately.  This attribute is "one-way-only" in that it starts
True and can be set False, but cannot be reset to True except
by restoring the graphics state in which is was still True.
This is intended to help control the behavior of plots when
embedded as subplots in a larger configuration.  Note that
this does not effect calls on `show_text()`; it only applies
to calls on `show_ylabel()`.

The text to be used for the title, or None indicating no title.

The text to be used for the x axis label, or None indicating
no label.

The text to be used for the y axis label, or None indicating
no label.