Update gfunc.m

fastalgorithms · Oct 23, 2024 · 1d1650b · 1d1650b
1 parent b9f0590
commit 1d1650b
Showing 1 changed file with 14 additions and 0 deletions.
diff --git a/chunkie/+chnk/+axissymlap2d/gfunc.m b/chunkie/+chnk/+axissymlap2d/gfunc.m
@@ -1,6 +1,15 @@
 function [gval,gdz,gdr,gdrp] = gfunc(r,rp,dr,z,zp,dz)
     domega3 = 2*pi;
     n       = 3;
+
+    t0 = (r == 0);
+    s0 = (rp == 0);
+    st0 = ~((~t0).*(~s0));
+    dz2 = dz.^2;
+    gval0 = 2*pi^2*rp./(sqrt(r.^2+rp.^2+dz2));
+
+    gdrp0 = -2*pi*(-4*pi^2)*rp.^2./(4*pi*sqrt(rp.^2+dz.^2).^3); 
+    gdz0 = -2*pi*(-4*pi^2)*rp.*dz./(4*pi*sqrt(rp.^2+dz.^2).^3); 
 
     t = (dz.^2+dr.^2)./(2.*r.*rp);
     [q0,q1,q0d] = chnk.axissymlap2d.qleg_half(t);
@@ -15,4 +24,9 @@
     rfac = -rp*(n-2)/2.*q0+(-(1+t).*rp+r).*q0d;
     gdr  = -domega3*(rp./r).^((n-2)/2)./(rp.*r) ...
           .*rfac;
+
+    gval(st0) = gval0(st0);
+    gdr(st0) = 0;
+    gdrp(st0) = gdrp0(st0);
+    gdz(st0) = gdz0(st0);
 end