From 5e8680c0d12fe107a1808bd77745c69a02be84b2 Mon Sep 17 00:00:00 2001
From: Tianyi Pu <912396513@qq.com>
Date: Sun, 11 Aug 2024 08:23:24 +0100
Subject: [PATCH] fix

---
 src/BandedSylvesters.jl        | 2 +-
 src/PseudostableRecurrences.jl | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/BandedSylvesters.jl b/src/BandedSylvesters.jl
index 79365be..dbbbb4e 100644
--- a/src/BandedSylvesters.jl
+++ b/src/BandedSylvesters.jl
@@ -28,7 +28,7 @@ end
 
 buffer(R::BandedSylvesterRecurrence) = R.buffer
 function rdiv!(P::BandedSylvesterRecurrence, x)
-    rdiv!(P.buffer)
+    rdiv!(P.buffer, x)
     P
 end
 
diff --git a/src/PseudostableRecurrences.jl b/src/PseudostableRecurrences.jl
index b87501f..d740935 100644
--- a/src/PseudostableRecurrences.jl
+++ b/src/PseudostableRecurrences.jl
@@ -20,9 +20,10 @@ export stable_recurrence, precision_shift
 Estimates `log2` of the amplification of `P` by performing a full recurrence based on random initial conditions.
 """
 function precision_shift(P::AbstractLinearRecurrencePlan)
-    test, _ = init(P; init=:rand)
-    shift = 1
-    testmax = 1.0
+    test, start = init(P; init=:rand)
+    shift = 4 # safe choice from experiments
+    testmax = norm(start, Inf)
+    rdiv!(test, testmax)
     while true
         v = step!(test)
         if isnothing(v)