From d85e90d2c6e77624d0a7f4a440101c519056478a Mon Sep 17 00:00:00 2001
From: Isuru Fernando <isuruf@gmail.com>
Date: Thu, 4 Oct 2018 21:45:06 -0500
Subject: [PATCH] automatically figure out the reduced coefficients
---
sumpy/expansion/__init__.py | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/sumpy/expansion/__init__.py b/sumpy/expansion/__init__.py
index a40aafde..54dbfd75 100644
--- a/sumpy/expansion/__init__.py
+++ b/sumpy/expansion/__init__.py
@@ -398,7 +398,7 @@ class LinearRecurrenceBasedExpansionTermsWrangler(ExpansionTermsWrangler):
:math:`S = N_{[r, :]}^{-T} N^T = N_{[r, :]}^{-T} N^T`.
"""
n = nullspace(pde_mat)
- idx = self.get_reduced_coeffs()
+ idx = self.get_reduced_coeffs(n)
assert len(idx) >= n.shape[1]
s = solve_symbolic(n.T[:, idx], n.T)
stored_identifiers = [mis[i] for i in idx]
@@ -455,11 +455,25 @@ class LinearRecurrenceBasedExpansionTermsWrangler(ExpansionTermsWrangler):
raise NotImplementedError
- def get_reduced_coeffs(self):
+ def get_reduced_coeffs(self, nullspace):
"""
Returns the indices of the reduced set of derivatives which are stored.
"""
- raise NotImplementedError
+ mat = nullspace.copy()
+ nrows = mat.shape[0]
+ ncols = mat.shape[1]
+ rows = []
+ for i in range(nrows):
+ for j in range(ncols):
+ if mat[i, j] != 0:
+ col = j
+ break
+ else:
+ continue
+ rows.append(i)
+ for j in range(i+1, nrows):
+ mat[j, :] = mat[i, col]*mat[j, :] - mat[i, :]*mat[j, col]
+ return rows
class LaplaceExpansionTermsWrangler(LinearRecurrenceBasedExpansionTermsWrangler):
@@ -477,7 +491,7 @@ class LaplaceExpansionTermsWrangler(LinearRecurrenceBasedExpansionTermsWrangler)
pde_dict[tuple(mi)] = 1
return pde_dict
- def get_reduced_coeffs(self):
+ def get_reduced_coeffs(self, nullspace):
idx = []
for i, mi in enumerate(self.get_full_coefficient_identifiers()):
# Return only the derivatives with the order of the last dimension
@@ -507,7 +521,7 @@ class HelmholtzExpansionTermsWrangler(LinearRecurrenceBasedExpansionTermsWrangle
pde_dict[tuple([0]*self.dim)] = 1
return pde_dict
- def get_reduced_coeffs(self):
+ def get_reduced_coeffs(self, nullspace):
idx = []
for i, mi in enumerate(self.get_full_coefficient_identifiers()):
# Return only the derivatives with the order of the last dimension
--
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