From 69fd19c01930f8cc43cc6b7204560d9bb2427c0d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Ne=C4=8Dada?= <marek@necada.org>
Date: Tue, 21 Apr 2020 11:56:22 +0300
Subject: [PATCH] SVD interval for general 2D lattice

Former-commit-id: f63e2fbd0d5d4dfd103654ca916f251251ba40a6
---
 misc/lat2d_realfreqsvd.py | 120 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100755 misc/lat2d_realfreqsvd.py

diff --git a/misc/lat2d_realfreqsvd.py b/misc/lat2d_realfreqsvd.py
new file mode 100755
index 0000000..916c9d4
--- /dev/null
+++ b/misc/lat2d_realfreqsvd.py
@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+
+import math
+from qpms.argproc import ArgParser, sfloat
+
+ap = ArgParser(['background', 'lattice2d', 'multi_particle',  'omega_seq'])
+
+ap.add_argument("-k", nargs=2, type=sfloat, required=True, help='k vector', metavar=('K_X', 'K_Y'))
+ap.add_argument("--kpi", action='store_true', help="Indicates that the k vector is given in natural units instead of SI, i.e. the arguments given by -k shall be automatically multiplied by pi / period (given by -p argument)")
+
+ap.add_argument("-g", "--little-group", type=str, default="trivial_g", help="Little group for subspace irrep classification", action="store")
+
+ap.add_argument("-o", "--output", type=str, required=False, help='output path (if not provided, will be generated automatically)')
+ap.add_argument("-O", "--plot-out", type=str, required=False, help="path to plot output (optional)")
+ap.add_argument("-P", "--plot", action='store_true', help="if -p not given, plot to a default path")
+ap.add_argument("-s", "--singular_values", type=int, default=10, help="Number of singular values to plot")
+
+a=ap.parse_args()
+
+import logging
+logging.basicConfig(format='%(asctime)s %(message)s', level=logging.INFO)
+
+
+#Important! The particles are supposed to be of D2h/D4h symmetry
+# thegroup = 'D4h' if px == py and not a.D2 else 'D2h'
+
+a1 = ap.direct_basis[0]
+a2 = ap.direct_basis[1]
+
+particlestr = "svdinterval" # TODO particle string specifier or some hash, do this in argproc.py
+defaultprefix = "%s_basis%gnm_%gnm__%gnm_%gnm_f(%g..%g..%g)eV_k%g_%g" % (
+    particlestr, a1[0]*1e9, a1[1]*1e9, a2[0]*1e9, a2[1]*1e9, *(a.eV_seq), ap.k[0], ap.k[1])
+logging.info("Default file prefix: %s" % defaultprefix)
+
+
+import numpy as np
+import qpms
+import warnings
+from qpms.cybspec import BaseSpec
+from qpms.cytmatrices import CTMatrix, TMatrixGenerator
+from qpms.qpms_c import Particle, pgsl_ignore_error
+from qpms.cymaterials import EpsMu, EpsMuGenerator, LorentzDrudeModel, lorentz_drude
+from qpms.cycommon import DebugFlags, dbgmsg_enable
+from qpms import FinitePointGroup, ScatteringSystem, BesselType, eV, hbar
+from qpms.symmetries import point_group_info 
+eh = eV/hbar
+
+# not used; TODO:
+irrep_labels = {"B2''":"$B_2''$",
+                "B2'":"$B_2'$",
+                "A1''":"$A_1''$",
+                "A1'":"$A_1'$",
+                "A2''":"$A_2''$",
+                "B1''":"$B_1''$",
+                "A2'":"$A_2'$", 
+                "B1'":"$B_1'$",
+                "E'":"$E'$",
+                "E''":"$E''$",}
+
+dbgmsg_enable(DebugFlags.INTEGRATION)
+
+
+
+omegas = ap.omegas
+
+logging.info("%d frequencies from %g to %g eV" % (len(omegas), omegas[0]/eh, omegas[-1]/eh))
+
+particles = ap.get_particles()
+
+ss, ssw = ScatteringSystem.create(particles, ap.background_emg, omegas[0], latticebasis=ap.direct_basis)
+k = np.array([ap.k[0], ap.k[1], 0])
+# Auxillary finite scattering system for irrep decomposition, quite a hack
+ss1, ssw1 = ScatteringSystem.create(particles, ap.background_emg, omegas[0],sym=FinitePointGroup(point_group_info[ap.little_group]))
+
+wavenumbers = np.empty(omegas.shape)
+SVs = [None] * ss1.nirreps
+for iri in range(ss1.nirreps):
+    SVs[iri] = np.empty(omegas.shape+(ss1.saecv_sizes[iri],))
+for i, omega in enumerate(omegas):
+    ssw = ss(omega)
+    wavenumbers[i] = ssw.wavenumber.real
+    if ssw.wavenumber.imag: 
+        warnings.warn("Non-zero imaginary wavenumber encountered")
+    with pgsl_ignore_error(15): # avoid gsl crashing on underflow; maybe not needed
+        ImTW = ssw.modeproblem_matrix_full(k)
+    for iri in range(ss1.nirreps):
+        ImTW_packed = ss1.pack_matrix(ImTW, iri)
+        SVs[iri][i] = np.linalg.svd(ImTW_packed, compute_uv = False)
+
+outfile = defaultprefix + ".npz" if a.output is None else a.output
+np.savez(outfile, meta=vars(a), omegas=omegas, wavenumbers=wavenumbers, SVs=np.concatenate(SVs, axis=-1), irrep_names=ss1.irrep_names, irrep_sizes=ss1.saecv_sizes, unitcell_area=ss.unitcell_volume
+       )
+logging.info("Saved to %s" % outfile)
+
+
+if a.plot or (a.plot_out is not None):
+    import matplotlib
+    matplotlib.use('pdf')
+    from matplotlib import pyplot as plt
+
+    fig = plt.figure()
+    ax = fig.add_subplot(111)
+    cc = plt.rcParams['axes.prop_cycle']()
+    for iri in range(ss1.nirreps):
+        cargs = next(cc)
+        nlines = min(a.singular_values, ss1.saecv_sizes[iri])
+        for i in range(nlines):
+            ax.plot(omegas/eh, SVs[iri][:,-1-i],
+                label= None if i else irrep_labels.get(ss1.irrep_names[iri], ss1.irrep_names[iri]), 
+                **cargs)
+    ax.set_ylim([0,1.1])
+    ax.set_xlabel('$\hbar \omega / \mathrm{eV}$')
+    ax.set_ylabel('Singular values')
+    ax.legend()
+    
+    plotfile = defaultprefix + ".pdf" if a.plot_out is None else a.plot_out
+    fig.savefig(plotfile)
+
+exit(0)
+