From 1342ef9683698c22aeabd113f44235a85320fe81 Mon Sep 17 00:00:00 2001
From: jatin <jagdish@kunato.io>
Date: Thu, 26 Sep 2024 23:57:58 +0530
Subject: [PATCH] updated readme.md with kurtosis example

---
 README.md  | 10 ++++++++++
 src/lib.rs |  9 ++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 8e63330..4344dae 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,15 @@ SELECT min_by(x, y) FROM VALUES (1, 10), (2, 5), (3, 15), (4, 8) as tab(x, y);
 -- | 2                   |
 -- +---------------------+
 
+-- Get the kurtosis value of a column of numeric data.
+SELECT kurtosis(col) FROM VALUES (1.0), (10.0), (100.0), (10.0), (1.0) as tab(col);
+-- Results in
+- +-------------------+
+- "| kurtosis(tab.col) |"
+- +-------------------+
+- "| 4.777292927667962 |"
+- +-------------------+
+
 ```
 
 ## Done
@@ -84,3 +93,4 @@ SELECT min_by(x, y) FROM VALUES (1, 10), (2, 5), (3, 15), (4, 8) as tab(x, y);
 - [x] `mode(expression) -> scalar` - Returns the most frequent (mode) value from a column of data.
 - [x] `max_by(expression1, expression2) -> scalar` - Returns the value of `expression1` associated with the maximum value of `expression2`.
 - [x] `min_by(expression1, expression2) -> scalar` - Returns the value of `expression1` associated with the minimum value of `expression2`.
+- [x] `kurtosis(expression) -> scalar` - Returns the kurtosis, a measure of the `tailedness` of the distribution, for the given numeric values in `expression`.
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index ee8f2ee..d79291c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -26,17 +26,24 @@ use datafusion::logical_expr::AggregateUDF;
 #[macro_use]
 pub mod macros;
 pub mod common;
+pub mod kurtosis;
 pub mod max_min_by;
 pub mod mode;
 
 pub mod expr_extra_fn {
+    pub use super::kurtosis::kurtosis;
     pub use super::max_min_by::max_by;
     pub use super::max_min_by::min_by;
     pub use super::mode::mode;
 }
 
 pub fn all_extra_aggregate_functions() -> Vec<Arc<AggregateUDF>> {
-    vec![mode_udaf(), max_min_by::max_by_udaf(), max_min_by::min_by_udaf(), kurtosis::kurtosis_udaf()]
+    vec![
+        mode_udaf(),
+        max_min_by::max_by_udaf(),
+        max_min_by::min_by_udaf(),
+        kurtosis::kurtosis_udaf(),
+    ]
 }
 
 /// Registers all enabled packages with a [`FunctionRegistry`]