From 6a0ed17109ad7936aa03540901e1d34247eb28ef Mon Sep 17 00:00:00 2001
From: Chris Nuernberger <chris@techascent.com>
Date: Sat, 4 Dec 2021 16:27:23 -0700
Subject: [PATCH] Regression caused by overeager linting.

---
 src/tech/v3/datatype/gradient.clj |  4 +++-
 test/tech/v3/datatype_test.clj    | 10 ++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/tech/v3/datatype/gradient.clj b/src/tech/v3/datatype/gradient.clj
index 3dbeb8b4..ebe727a4 100644
--- a/src/tech/v3/datatype/gradient.clj
+++ b/src/tech/v3/datatype/gradient.clj
@@ -115,7 +115,9 @@ user> (dt-grad/diff1d [1 2 4])
   [data & [options]]
   (let [reader (dt-base/->buffer data)
         op-space (casting/simple-operation-space (.elemwiseDatatype reader))
-        options (or options {})]
+        options (or options {})
+        n-data (.lsize reader)
+        addval (or (options :prepend) (options :append))]
     (errors/when-not-errorf
      (not (and (options :prepend) (options :append)))
      "prepend and append options cannot be used simultaneously")
diff --git a/test/tech/v3/datatype_test.clj b/test/tech/v3/datatype_test.clj
index 393a76b7..55e05cb6 100644
--- a/test/tech/v3/datatype_test.clj
+++ b/test/tech/v3/datatype_test.clj
@@ -7,6 +7,8 @@
             [tech.v3.datatype.functional :as dfn]
             [tech.v3.datatype.argops :as argops]
             [tech.v3.datatype.rolling :as rolling]
+            [tech.v3.datatype.gradient :as dt-grad]
+            [tech.v3.datatype.wavelet]
             [tech.v3.datatype.datetime])
   (:import [java.nio FloatBuffer]
            [java.util ArrayList]))
@@ -781,5 +783,9 @@
 (deftest mean-sum-forgiveness
   (let [test-data [Double/NaN 1 2]]
     (is (not (Double/isNaN (dfn/sum test-data))))
-    (is (not (Double/isNaN (dfn/mean test-data)))))
-  )
+    (is (not (Double/isNaN (dfn/mean test-data))))))
+
+
+(deftest gradient-correct
+  (is (= (vec (repeat 10 1.0))
+         (dt-grad/gradient1d (range 10)))))