Introduce graphics insets

[egourgoulhon]

This ticket introduces graphics insets, i.e. it allows to have various Graphics objects at arbitrary locations and sizes on a single figure. Previously, only graphics arrays, i.e. Graphics objects arranged in a regular array, were possible.

This is made possible thanks to the generic class MultiGraphics introduced in #27865.
The user interface is constituted of three new functions:

• the method Graphics.inset(), which adds an inset to a given graphics; see this preview example
• the method MultiGraphics.inset(), which adds an inset to a multi-graphics (e.g. a GraphicsArray); see this preview example
• the function multi_graphics() , which creates a figure from a list of Graphics objects at user-specified locations; see this preview example

Depends on #27865

CC: @kcrisman @fchapoton @dkrenn @jdemeyer @embray

Component: graphics

Keywords: graphics inset

Author: Eric Gourgoulhon

Branch: ed586d3

Reviewer: Markus Wageringel

Issue created by migration from https://trac.sagemath.org/ticket/27866

[egourgoulhon]

Author: Eric Gourgoulhon

[egourgoulhon]

Branch: public/graphics/graphics_insets

[egourgoulhon]

Commit: e177646

[egourgoulhon]

Dependencies: #27865

[egourgoulhon]

Last 10 new commits:

1bf8ad1	Small cleaning in MultiGraphics
ccff60c	Fix some doctests after the improved computation of nrows and ncols in graphics_array
26180ab	Some cleaning in MultiGraphics.matplotlib
3bd6a56	Minor cleaning in GraphicsArray
3a5ef55	Change index range in GraphicsArray._add_subplot()
60ede56	First draft of multi_graphics
e58adf3	Add method inset() to Graphics and MultiGraphics
26a8eb5	Add method position in MultiGraphics and GraphicsArray
8ce0db3	Add transparency of individual graphics in MultiGraphics + more doctests
e177646	Add documentation to MultiGraphics

[egourgoulhon]

Description changed:

--- 
+++ 
@@ -1,7 +1,8 @@
 This ticket introduces graphics insets, i.e. it allows to have various `Graphics` objects at arbitrary locations and sizes on a single figure. Previously, only graphics arrays, i.e. `Graphics` objects arranged in a regular array, were possible. 
 
 This is made possible thanks to the generic class `MultiGraphics` introduced in #27865.
-The user interface is constituted of two new functions:
-- the method `Graphics.inset()`, which attaches an inset to a given graphics; see this [preview example](https://sagemanifolds.obspm.fr/preview/graphics_inset/reference/plotting/sage/plot/graphics.html#sage.plot.graphics.Graphics.inset)
-- the function `multi_graphics()` , which allows to create a figure from a list of `Graphics` objects at user-specified locations; see this [preview example](https://sagemanifolds.obspm.fr/preview/graphics_inset/reference/plotting/sage/plot/plot.html#sage.plot.plot.multi_graphics)
+The user interface is constituted of three new functions:
+- the method `Graphics.inset()`, which adds an inset to a given graphics; see this [preview example](https://sagemanifolds.obspm.fr/preview/graphics_inset/reference/plotting/sage/plot/graphics.html#sage.plot.graphics.Graphics.inset)
+- the method `MultiGraphics.inset()`, which adds an inset to a multi-graphics (e.g. a `GraphicsArray`); see this [preview example](https://sagemanifolds.obspm.fr/preview/graphics_inset/reference/plotting/sage/plot/multigraphics.html#sage.plot.multigraphics.MultiGraphics.inset)
+- the function `multi_graphics()` , which creates a figure from a list of `Graphics` objects at user-specified locations; see this [preview example](https://sagemanifolds.obspm.fr/preview/graphics_inset/reference/plotting/sage/plot/plot.html#sage.plot.plot.multi_graphics)
 

[embray]

comment:5

Moving tickets from the Sage 8.8 milestone that have been actively worked on in the last six months to the next release milestone (optimistically).