Maint (#337)

* Reduce code by making use of new SciPy new features (complex-valued map_coordinate; lazy loading).
* Add current year to docs

CHANGELOG.rst

@@ -9,7 +9,11 @@ Changelog
 latest
 ------
 
-- Add notes for ``ipympl`` (interactive plots in modern Jupyter).
+Maintenance
+
+  - Add notes for ``ipympl`` (interactive plots in modern Jupyter).
+  - Reduce code by making use of new SciPy new features (complex-valued
+    map_coordinate; lazy loading).
 
 
 v1.8.3 : tol_gradient isfinite

docs/conf.py

@@ -1,3 +1,4 @@
+import time
 from emg3d import __version__
 
 # ==== 1. Extensions  ====
@@ -56,7 +57,7 @@
 # General information about the project.
 project = 'emg3d'
 author = 'The emsig community'
-copyright = f'2018, {author}'
+copyright = f'2018-{time.strftime("%Y")}, {author}'
 
 # |version| and |today| tags (|release|-tag is not used).
 version = __version__

emg3d/maps.py

@@ -545,15 +545,7 @@ def interp_spline_3d(points, values, xi, **kwargs):
             bounds_error=False, fill_value='extrapolate'
         )(xi[:, i])
 
-    # `map_coordinates` only works for real data; split it up if complex.
-    # Note: SciPy 1.6 (12/2020) introduced complex-valued
-    #       ndimage.map_coordinates; replace eventually.
-    values_x = sp.ndimage.map_coordinates(values.real, coords, **kwargs)
-    if 'complex' in values.dtype.name:
-        imag = sp.ndimage.map_coordinates(values.imag, coords, **kwargs)
-        values_x = values_x + 1j*imag
-
-    return values_x
+    return sp.ndimage.map_coordinates(values, coords, **kwargs)
 
 
 @nb.njit(**_numba_setting)

emg3d/solver.py

@@ -32,8 +32,6 @@
 
 import numpy as np
 import scipy as sp
-import scipy.linalg as sl
-import scipy.sparse.linalg as ssl
 
 from emg3d import core, meshes, models, fields, utils
 
@@ -311,7 +309,7 @@ def solve(model, sfield, sslsolver=True, semicoarsening=True,
     var.cprint(var, 2)
 
     # Compute reference error for tolerance.
-    var.l2_refe = sl.norm(sfield.field, check_finite=False)
+    var.l2_refe = sp.linalg.norm(sfield.field, check_finite=False)
     var.error_at_cycle[0] = var.l2_refe
 
     # Check sfield.
@@ -704,7 +702,7 @@ def amatvec(efield):
         return -rfield.field
 
     # Initiate LinearOperator A x.
-    A = ssl.LinearOperator(
+    A = sp.sparse.linalg.LinearOperator(
             shape=(sfield.field.size, sfield.field.size),
             dtype=sfield.field.dtype, matvec=amatvec)
 
@@ -725,7 +723,7 @@ def mg_matvec(sfield):
     # Initiate LinearOperator M.
     M = None
     if var.cycle:
-        M = ssl.LinearOperator(
+        M = sp.sparse.linalg.LinearOperator(
                 shape=(sfield.field.size, sfield.field.size),
                 dtype=sfield.field.dtype, matvec=mg_matvec)
 
@@ -762,7 +760,7 @@ def callback(x):
     # The ssl solvers do not abort if the norm diverges or is not finite. We
     # therefore throw an exception in `_terminate`, and catch it here.
     try:
-        efield.field, i = getattr(ssl, var.sslsolver)(
+        efield.field, i = getattr(sp.sparse.linalg, var.sslsolver)(
                 A=A, b=sfield.field, x0=efield.field, **{TOL: var.tol},
                 maxiter=var.ssl_maxit, atol=1e-30, M=M, callback=callback)
     except _ConvergenceError:
@@ -1065,7 +1063,7 @@ def residual(model, sfield, efield, norm=False):
 
     # Return error if norm.
     if norm:
-        return sl.norm(rfield.field, check_finite=False)
+        return sp.linalg.norm(rfield.field, check_finite=False)
 
     # Return residual if not norm.
     else: