Magnetic fields are now expressed in units of magnetic flux quantum
per unit area.

We still refer to these as "phases" everywhere in the code.
Working with phase factors means that users do not have to
exponentiate anything (and potentially get an incorrect sign).
In addition this is closer to what we need for non-abelian
gauge fields.

This means less repeated documentation.

Co-authored-by: Pablo Piskunow <pablo.perez.piskunow@gmail.com>
Co-authored-by: Daniel Varjas <dvarjas@gmail.com>

The UI will show the test failures as warnings (which we can
address).

Add first and second derivative calculation to kwant.physics.Bands,
and allow eigenvectors to be optionally returned.

See merge request kwant/kwant!262

The 'out' parameter is only used when you don't want numpy to
allocate a new array for the result, which is not the case here.

Thomas Kloss authored 6 years ago and Joseph Weston committed 6 years ago

np.linalg.eigvalsh returns eigenvalues already in ascending order

There is nothing that consumes lead_paddings right now, but it will be useful
for plotting and gauge fixing.
Closes #266.

Closes #232.
We can further improve on this behavior if we provide a useful class of
callables that can efficiently represent itself in printed form, however this
change is an immediate improvement of plot quality.

maint: clear up warnings in tests

See merge request kwant/kwant!270

This silences a deprecation warning on scipy < 1.2 and numpy > 1.15.

add automatic Peierls phase calculation

Closes #19

See merge request kwant/kwant!219

Co-authored-by: Pablo Piskunow <pablo.perez.piskunow@gmail.com>
Co-authored-by: Daniel Varjas <dvarjas@gmail.com>

use the shift-inverse method for finding sparse eigenvalues
in the finite system tutorial.

See merge request kwant/kwant!265

This avoids "sparse efficiency" warnings.

add testing environment specification as Dockerfiles and conda environments

See merge request kwant/kwant!260

Sometimes the testing jobs fail because the build artifacts
are removed.

Only builds testing images when the relevant dockerfile/conda envs
have changed.