From ec6aca850d840f28ad04353d908d757ed8b00b1a Mon Sep 17 00:00:00 2001
From: Matthias Mohr <m.mohr@uni-muenster.de>
Date: Thu, 2 Jul 2020 15:09:54 +0200
Subject: [PATCH 1/2] Clarify mod process #168

---
 CHANGELOG.md |  3 ++-
 mod.json     | 13 +++++++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21d3fb71..2b4acd19 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,8 +30,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `filter_bbox`, `load_collection`, `resample_spatial`: Fixed invalid EPSG code examples.
 - `aggregate_temporal`: Fixed outdated message for exception `TooManyDimensions`.
 - `clip`: Fixed examples.
+- `mean`: Clarify behaviour for arrays with `null`-values only.
+- `mod`: Clarified behaviour. [#168](https://github.com/Open-EO/openeo-processes/issues/168)
 - `resample_*`: Clarified behaviour.
-- `mean`: Clarify behavior for arrays with `null`-values only.
 
 ## 1.0.0-rc.1 - 2020-01-31
 
diff --git a/mod.json b/mod.json
index c9ed9ce1..132c41c9 100644
--- a/mod.json
+++ b/mod.json
@@ -1,7 +1,7 @@
 {
     "id": "mod",
     "summary": "Modulo",
-    "description": "Remainder after division of `x` by `y`.\n\nThe result of a modulo operation has the sign of the divisor. The handling regarding the sign of the result [differs between programming languages](https://en.wikipedia.org/wiki/Modulo_operation) and needs careful consideration while implementing this process.\n\nThe no-data value `null` is passed through and therefore gets propagated if any of the arguments is `null`.",
+    "description": "Remainder after division of `x` by `y` for both integers and floating-point numbers.\n\nThe result of a modulo operation has the sign of the divisor. The handling regarding the sign of the result [differs between programming languages](https://en.wikipedia.org/wiki/Modulo_operation#In_programming_languages) and needs careful consideration to avoid unexpected results. To remove the sign, use the process ``absolute()``.\n\nThe no-data value `null` is passed through and therefore gets propagated if any of the arguments is `null`. A modulo by zero results in ±infinity if the processing environment supports it. Otherwise a `DivisionByZero` error must the thrown.",
     "categories": [
         "math"
     ],
@@ -36,6 +36,11 @@
             ]
         }
     },
+    "exceptions": {
+        "DivisionByZero": {
+            "message": "Division by zero is not supported."
+        }
+    },
     "examples": [
         {
             "arguments": {
@@ -53,10 +58,10 @@
         },
         {
             "arguments": {
-                "x": 27,
-                "y": -5
+                "x": 3.14,
+                "y": -2
             },
-            "returns": -3
+            "returns": -0.86
         },
         {
             "arguments": {

From 996b631d925abd08974f218d83714ce619bf09ec Mon Sep 17 00:00:00 2001
From: Matthias Mohr <m.mohr@uni-muenster.de>
Date: Thu, 2 Jul 2020 16:38:16 +0200
Subject: [PATCH 2/2] Leave it up to the mathematicians ;-)

---
 mod.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mod.json b/mod.json
index 132c41c9..5409df05 100644
--- a/mod.json
+++ b/mod.json
@@ -1,7 +1,7 @@
 {
     "id": "mod",
     "summary": "Modulo",
-    "description": "Remainder after division of `x` by `y` for both integers and floating-point numbers.\n\nThe result of a modulo operation has the sign of the divisor. The handling regarding the sign of the result [differs between programming languages](https://en.wikipedia.org/wiki/Modulo_operation#In_programming_languages) and needs careful consideration to avoid unexpected results. To remove the sign, use the process ``absolute()``.\n\nThe no-data value `null` is passed through and therefore gets propagated if any of the arguments is `null`. A modulo by zero results in ±infinity if the processing environment supports it. Otherwise a `DivisionByZero` error must the thrown.",
+    "description": "Remainder after division of `x` by `y` for both integers and floating-point numbers.\n\nThe result of a modulo operation has the sign of the divisor. The handling regarding the sign of the result [differs between programming languages](https://en.wikipedia.org/wiki/Modulo_operation#In_programming_languages) and needs careful consideration to avoid unexpected results.\n\nThe no-data value `null` is passed through and therefore gets propagated if any of the arguments is `null`. A modulo by zero results in ±infinity if the processing environment supports it. Otherwise a `DivisionByZero` error must the thrown.",
     "categories": [
         "math"
     ],