From d0c17de1545a76f52499da30567cde98b4af61f4 Mon Sep 17 00:00:00 2001
From: Koki Fushimi <paalon1936@gmail.com>
Date: Tue, 3 Mar 2020 18:50:50 +0900
Subject: [PATCH] =?UTF-8?q?Update=20squarewave(x,=20=CE=B8)=20to=20throw?=
 =?UTF-8?q?=20DomainError.?=
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---
 src/Waveforms.jl | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Waveforms.jl b/src/Waveforms.jl
index ed8e889..e3199f9 100644
--- a/src/Waveforms.jl
+++ b/src/Waveforms.jl
@@ -21,7 +21,10 @@ squarewave(x::Real) = ifelse(mod2pi(x) < π, 1.0, -1.0)
 Compute ``2\pi``-periodic square wave of `x` with a duty cycle `θ`
 and a peak amplitude ``1``.
 """
-squarewave(x::Real, θ::Real) = ifelse(mod2pi(x) < 2π * θ, 1.0, -1.0)
+function squarewave(x::Real, θ::Real)
+    0 ≤ θ ≤ 1 || throw(DomainError(θ, "squwarewave(x, θ) is only defined for 0 ≤ θ ≤ 1."))
+    ifelse(mod2pi(x) < 2π * θ, 1.0, -1.0)
+end
 
 @doc raw"""
     squarewave1(x)