Extended GiNaC interface to inum

checks/test.f90

@@ -413,7 +413,7 @@ CONTAINS
     if (what .eq. 0) then
       evalt = G(arr(1:l))
     elseif (what.eq.1) then
-      evalt = geval(arr(1:l),l)
+      evalt = geval(toinum(arr(1:l)),l)
     endif
   end function
 

src/ginac.cpp

@@ -5,18 +5,25 @@ using namespace GiNaC;
 #include <iostream>
 
 typedef struct {double r,i;} complex_t;
+typedef struct {complex_t c; signed char i0;} inum_t;
 extern "C"{
-complex_t geval_(complex_t * z, int* n);
+complex_t geval_(inum_t * z, int* n);
 };
-complex_t geval_(complex_t * z, int* n) {
+
+complex_t geval_(inum_t * z, int* n) {
   cln::cl_inhibit_floating_point_underflow = true;
-  lst w;
+  lst w,s;
   for(long i=0;i<(*n)-1;i++)
   {
-    w.append((z->r)+(z->i)*I);
+    ex zz;
+    if (abs(z->c.i) < 1e-15)
+      w.append((z->c.r));
+    else
+      w.append((z->c.r)+(z->c.i)*I);
+    s.append(z->i0);
     z++;
   }
-  ex ans = G(w,z->r).evalf();
+  ex ans = G(w,s,z->c.r).evalf();
   return {
     .r = ex_to<numeric>(evalf(real_part(ans))).to_double(),
     .i = ex_to<numeric>(evalf(imag_part(ans))).to_double()

[ulrich_y]

There is a subtlety in GiNaC. The explicitly given ieps prescription for value is ignored if

   cln::instanceof(value, cln::cl_R_ring)

Of course it would make sense to ignore the explicit value if value is indeed complex (cf. 63b4cc59). However, even if it is real, my old C++ interface

  for(long i=0;i<(*n)-1;i++)
  {
    w.append((z->r)+(z->i)*I);
    z++;
  }

would create an cln::cl_R_ring. We now check whether z is real and act accordingly.