Closes #279.

Closes #214.

'temp' is too short a parameter name, especially for an API,
and could be confused with 'temporary'.

This avoids "sparse efficiency" warnings.

Christoph Groth authored 6 years ago and Joseph Weston committed 6 years ago

and without default values.

Co-authored-by: Joseph Weston <joseph@weston.cloud>

'box-forced' is deprecated as of matplotlib 2.2.

The problem was introduced in commit 7c802539.

The lattice constant is never changed from 1, and in addition can be
varied independently of the 't' and 'α' parameters; This should not
be the case if the model is meant to be derived from a discretization
of a continuum model. We remove the lattice constant to limit confusion.

For a spin-orbit term of the form '-iασ_y∂_x' the hopping
for 'HoppingKind((1, 0), lat)' (*from* 'x' *to* 'x + a')
is 'iασ_y/2'.

Closes #175.

Previously, an erroneous current was shown at *zero* magnetic field,
which was due to a choice of degenerate eigenvalue. Now we evaluate
the current and density at finite magnetic field, to demonstrate
the intended effect.

Closes #150.

Previously a point defect introduced by an incorrect treatment
of the origin produced erroneous scattering. We also update the text
to reflect the actual magnetic potential used.

Closes #156.

I assume that most people encounter the tutorial example scripts by
reading the documentation, and not by viewing the tutorial subdirectory
of a checked-out Kwant source.

That's the motivation for moving all the manipulations of tutorial
scripts from setup.py to doc/Makefile.  Previously, a successful 'make
html' would require a preceding execution of 'setup.py build_tut'.  Now,
a simple 'make html' is enough.

While at it, I reorganized where the example scripts and their outputs
are stored.  Everything is now in 'doc/source/code' with its three
subdirectories 'download' (to be shown to readers), 'include' (with
include markers), and 'figure' (figure generation & figures).  This
organization is clearer and also makes the generation of figures
separate from the tutorial.