From 6300d343566390120defa1190e84e92a457d31c9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Crozet?= <developer@crozet.re>
Date: Sat, 13 Jun 2020 10:06:48 +0200
Subject: [PATCH] Add the ::ith constructor for vectors.

This initializes a vectors to zero except the i-th element set to a given value.
---
 src/base/construction.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/base/construction.rs b/src/base/construction.rs
index ae8c10d4..f810acdf 100644
--- a/src/base/construction.rs
+++ b/src/base/construction.rs
@@ -1011,6 +1011,14 @@ where
     N: Scalar + Zero + One,
     DefaultAllocator: Allocator<N, R>,
 {
+    /// The column vector with `val` as its i-th component.
+    #[inline]
+    pub fn ith(i: usize, val: N) -> Self {
+        let mut res = Self::zeros();
+        res[i] = val;
+        res
+    }
+
     /// The column vector with a 1 as its first component, and zero elsewhere.
     #[inline]
     pub fn x() -> Self