initialize dlr2d_rf index 2 for singular terms

Wentzell · claude · Wentzell · commit a446d5cca643 · 2026-01-21T11:08:34.000-05:00
Co-Authored-By: Claude &lt;noreply@anthropic.com&gt;
diff --git a/c++/cppdlr2d/dlr2d.cpp b/c++/cppdlr2d/dlr2d.cpp
@@ -129,8 +129,11 @@ build_dlr2d(double lambda, double eps, bool compressgrid, bool compressbasis) {
       dlr2d_rf(i, 1) = k;
       dlr2d_rf(i, 2) = l;
     } else {
+      // Singular term: only one real frequency index k
+      // Set l = k due to δ_{l,k} factor in the singular term
       dlr2d_rf(i, 0) = 3;
       dlr2d_rf(i, 1) = idx - 3 * r * r;
+      dlr2d_rf(i, 2) = idx - 3 * r * r;
     }
   }
 

Original file line number	Diff line number	Diff line change
`@@ -129,8 +129,11 @@ build_dlr2d(double lambda, double eps, bool compressgrid, bool compressbasis) {`
`129`	`129`	`dlr2d_rf(i, 1) = k;`
`130`	`130`	`dlr2d_rf(i, 2) = l;`
`131`	`131`	`} else {`
	`132`	`+ // Singular term: only one real frequency index k`
	`133`	`+ // Set l = k due to δ_{l,k} factor in the singular term`
`132`	`134`	`dlr2d_rf(i, 0) = 3;`
`133`	`135`	`dlr2d_rf(i, 1) = idx - 3 * r * r;`
	`136`	`+ dlr2d_rf(i, 2) = idx - 3 * r * r;`
`134`	`137`	`}`
`135`	`138`	`}`
`136`	`139`