From 86716755a439341a05100ba6ee4f0f314e3699c8 Mon Sep 17 00:00:00 2001
From: VisruthSK <public@visruth.com>
Date: Thu, 9 Jul 2026 23:05:45 -0700
Subject: [PATCH] Restore original loo k behaviour

---
 R/psis.R                   | 3 +++
 tests/testthat/test_psis.R | 8 +++-----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/R/psis.R b/R/psis.R
index 463d8caf..dd8b0176 100644
--- a/R/psis.R
+++ b/R/psis.R
@@ -257,6 +257,9 @@ psis_smooth_tail <- function(x, cutoff) {
   fit <- posterior::gpdfit(exp(x) - exp_cutoff, sort_x = FALSE)
   k <- fit$k
   sigma <- fit$sigma
+  if (is.na(k)) {
+    k <- Inf
+  }
   if (is.finite(k)) {
     p <- (seq_len(len) - 0.5) / len
     qq <- posterior::qgeneralized_pareto(p, 0, sigma, k) + exp_cutoff
diff --git a/tests/testthat/test_psis.R b/tests/testthat/test_psis.R
index d43b6ed0..93d7501a 100644
--- a/tests/testthat/test_psis.R
+++ b/tests/testthat/test_psis.R
@@ -153,11 +153,9 @@ test_that("do_psis_i throws warning if all tail values the same", {
 })
 
 test_that("psis_smooth_tail returns original tail values if k is infinite", {
-  # skip on M1 Mac until we figure out why this test fails only on M1 Mac
-  skip_if(Sys.info()[["sysname"]] == "Darwin" && R.version$arch == "aarch64")
-
-  xx <- c(1, 2, 3, 4, 4, 4, 4, 4, 4, 4, 4)
-  val <- suppressWarnings(psis_smooth_tail(xx, 3))
+  xx <- log(c(2, 2, 2, 2, 3, 4, 5, 6))
+  val <- suppressWarnings(psis_smooth_tail(xx, 0))
   expect_equal(val$tail, xx)
   expect_equal(val$k, Inf)
 })
+