From 7fdddedaf09993365e91cdde98bf96b4aa4a72f5 Mon Sep 17 00:00:00 2001
From: Yi Jiang <yijiangcontact@gmail.com>
Date: Wed, 3 Jan 2024 15:30:37 -0500
Subject: [PATCH 1/3] Binary search in times

---
 ql/models/parameter.hpp | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/ql/models/parameter.hpp b/ql/models/parameter.hpp
index ac126f86044..f5e8d2051e8 100644
--- a/ql/models/parameter.hpp
+++ b/ql/models/parameter.hpp
@@ -123,12 +123,8 @@ namespace QuantLib {
             explicit Impl(std::vector<Time> times) : times_(std::move(times)) {}
 
             Real value(const Array& params, Time t) const override {
-                Size size = times_.size();
-                for (Size i=0; i<size; i++) {
-                    if (t<times_[i])
-                        return params[i];
-                }
-                return params[size];
+                Size i = upper_bound(times_.begin(), times_.end(), t) - times_.begin();
+                return params[i-(i!=0)];
             }
 
           private:

From 745516bcc9828413c1a1d842efc5f769964cffb9 Mon Sep 17 00:00:00 2001
From: Yi Jiang <yijiangcontact@gmail.com>
Date: Wed, 3 Jan 2024 15:35:37 -0500
Subject: [PATCH 2/3] forgot std::

---
 ql/models/parameter.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ql/models/parameter.hpp b/ql/models/parameter.hpp
index f5e8d2051e8..a2ed1dba7dd 100644
--- a/ql/models/parameter.hpp
+++ b/ql/models/parameter.hpp
@@ -123,7 +123,7 @@ namespace QuantLib {
             explicit Impl(std::vector<Time> times) : times_(std::move(times)) {}
 
             Real value(const Array& params, Time t) const override {
-                Size i = upper_bound(times_.begin(), times_.end(), t) - times_.begin();
+                Size i = std::upper_bound(times_.begin(), times_.end(), t) - times_.begin();
                 return params[i-(i!=0)];
             }
 

From 4923b7996d55b48ca617da5f698d0437b6133ed6 Mon Sep 17 00:00:00 2001
From: Yi Jiang <yijiangcontact@gmail.com>
Date: Thu, 4 Jan 2024 19:15:18 -0500
Subject: [PATCH 3/3] Shouldn't subtract 1, what was I thinking?

---
 ql/models/parameter.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ql/models/parameter.hpp b/ql/models/parameter.hpp
index a2ed1dba7dd..2ce1f99007c 100644
--- a/ql/models/parameter.hpp
+++ b/ql/models/parameter.hpp
@@ -124,7 +124,7 @@ namespace QuantLib {
 
             Real value(const Array& params, Time t) const override {
                 Size i = std::upper_bound(times_.begin(), times_.end(), t) - times_.begin();
-                return params[i-(i!=0)];
+                return params[i];
             }
 
           private: