From 7ae268345404a76836a4d084646f70201d6d1e2a Mon Sep 17 00:00:00 2001
From: p15-git-acc <37548430+p15-git-acc@users.noreply.github.com>
Date: Tue, 19 Feb 2019 05:37:40 -0600
Subject: [PATCH] make corrections to zeta_zeros

---
 acb_dirichlet.h                      |  2 +-
 acb_dirichlet/hardy_z_zero.c         | 17 +----------------
 acb_dirichlet/isolate_hardy_z_zero.c |  2 ++
 acb_dirichlet/zeta_zero.c            |  5 ++---
 acb_dirichlet/zeta_zeros.c           |  4 ++++
 5 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/acb_dirichlet.h b/acb_dirichlet.h
index 19852903..288cdabb 100644
--- a/acb_dirichlet.h
+++ b/acb_dirichlet.h
@@ -177,7 +177,7 @@ void _acb_dirichlet_refine_hardy_z_zero(arb_t res, const arf_t a, const arf_t b,
 void acb_dirichlet_hardy_z_zero(arb_t res, const fmpz_t n, slong prec);
 void acb_dirichlet_hardy_z_zeros(arb_ptr res, const fmpz_t n, slong len, slong prec);
 void acb_dirichlet_zeta_zero(acb_t res, const fmpz_t n, slong prec);
-void acb_dirichlet_zeta_zeros(acb_t res, const fmpz_t n, slong len, slong prec);
+void acb_dirichlet_zeta_zeros(acb_ptr res, const fmpz_t n, slong len, slong prec);
 void _acb_dirichlet_exact_zeta_nzeros(fmpz_t res, const arf_t t);
 void acb_dirichlet_zeta_nzeros(arb_t res, const arb_t t, slong prec);
 void acb_dirichlet_backlund_s(arb_t res, const arb_t t, slong prec);
diff --git a/acb_dirichlet/hardy_z_zero.c b/acb_dirichlet/hardy_z_zero.c
index 2e5cf4f0..4eaf2896 100644
--- a/acb_dirichlet/hardy_z_zero.c
+++ b/acb_dirichlet/hardy_z_zero.c
@@ -174,20 +174,5 @@ _acb_dirichlet_refine_hardy_z_zero(arb_t res,
 void
 acb_dirichlet_hardy_z_zero(arb_t res, const fmpz_t n, slong prec)
 {
-    arf_t a, b;
-
-    if (fmpz_cmp_si(n, 1) < 0)
-    {
-        flint_printf("n must be positive\n");
-        flint_abort();
-    }
-
-    arf_init(a);
-    arf_init(b);
-
-    acb_dirichlet_isolate_hardy_z_zero(a, b, n);
-    _acb_dirichlet_refine_hardy_z_zero(res, a, b, prec);
-
-    arf_clear(a);
-    arf_clear(b);
+    acb_dirichlet_hardy_z_zeros(res, n, 1, prec);
 }
diff --git a/acb_dirichlet/isolate_hardy_z_zero.c b/acb_dirichlet/isolate_hardy_z_zero.c
index bc886a70..d0cee1a3 100644
--- a/acb_dirichlet/isolate_hardy_z_zero.c
+++ b/acb_dirichlet/isolate_hardy_z_zero.c
@@ -1268,6 +1268,8 @@ acb_dirichlet_hardy_z_zeros(arb_ptr res, const fmpz_t n, slong len, slong prec)
         flint_printf("n must be positive\n");
         flint_abort();
     }
+    if (len <= 0)
+        return;
     fmpz_init(k);
     c = 0;
     while (c < len)
diff --git a/acb_dirichlet/zeta_zero.c b/acb_dirichlet/zeta_zero.c
index 887f4781..f1839bb6 100644
--- a/acb_dirichlet/zeta_zero.c
+++ b/acb_dirichlet/zeta_zero.c
@@ -20,14 +20,13 @@ acb_dirichlet_zeta_zero(acb_t res, const fmpz_t n, slong prec)
     switch (fmpz_sgn(n))
     {
         case -1:
-            acb_set_d(res, 0.5);
             fmpz_neg(k, n);
-            acb_dirichlet_hardy_z_zero(acb_imagref(res), k, prec);
+            acb_dirichlet_zeta_zeros(res, k, 1, prec);
             acb_conj(res, res);
             break;
         case 1:
             acb_set_d(res, 0.5);
-            acb_dirichlet_hardy_z_zero(acb_imagref(res), n, prec);
+            acb_dirichlet_zeta_zeros(res, n, 1, prec);
             break;
         default:
             acb_indeterminate(res);
diff --git a/acb_dirichlet/zeta_zeros.c b/acb_dirichlet/zeta_zeros.c
index d39f554c..833132fe 100644
--- a/acb_dirichlet/zeta_zeros.c
+++ b/acb_dirichlet/zeta_zeros.c
@@ -19,6 +19,10 @@ acb_dirichlet_zeta_zeros(acb_ptr res, const fmpz_t n, slong len, slong prec)
     {
         acb_indeterminate(res);
     }
+    else if (len <= 0)
+    {
+        return;
+    }
     else
     {
         slong i;