RFC: Some degree trigonometric functions, sind, cosd, tand, `as…

…ind` , `acosd`, `asecd`, `acsd`, `acotd`, `atand` accept a square matrix. (JuliaLang#39758)

* Some degree trigonometric functions, `sind`, `cosd`, `tand`, `asind`, `acosd`, `asecd`, `acsd`, `acotd` accept an square matrix.

* add PR number and change argument name to be the same as in the document.

* Update NEWS.md

* add `atand` for News.md.

Co-authored-by: Viral B. Shah <ViralBShah@users.noreply.github.com>

NEWS.md

@@ -89,6 +89,7 @@ Standard library changes
   ([#39322])
 * `@lock` is now exported from Base ([#39588]).
 * The experimental function `Base.catch_stack()` has been renamed to `current_exceptions()`, exported from Base and given a more specific return type ([#29901])
+* Some degree trigonometric functions, `sind`, `cosd`, `tand`, `asind`, `acosd`, `asecd`, `acscd`, `acotd`, `atand` now accept an square matrix ([#39758]).
 
 #### Package Manager
 

base/special/trig.jl

@@ -1269,22 +1269,30 @@ end
 sincosd(::Missing) = (missing, missing)
 
 for (fd, f, fn) in ((:sind, :sin, "sine"), (:cosd, :cos, "cosine"), (:tand, :tan, "tangent"))
-    name = string(fd)
-    @eval begin
-        @doc """
-            $($name)(x)
-        Compute $($fn) of `x`, where `x` is in degrees. """ ($fd)(z) = ($f)(deg2rad(z))
+    for (fu, un) in ((:deg2rad, "degrees"),)
+        name = string(fd)
+        @eval begin
+            @doc """
+                $($name)(x)
+
+            Compute $($fn) of `x`, where `x` is in $($un).
+            If `x` is a matrix, `x` needs to be a square matrix. """ ($fd)(x) = ($f)(($fu).(x))
+        end
     end
 end
 
 for (fd, f, fn) in ((:asind, :asin, "sine"), (:acosd, :acos, "cosine"),
                     (:asecd, :asec, "secant"), (:acscd, :acsc, "cosecant"), (:acotd, :acot, "cotangent"))
-    name = string(fd)
-    @eval begin
-        @doc """
-            $($name)(x)
 
-        Compute the inverse $($fn) of `x`, where the output is in degrees. """ ($fd)(y) = rad2deg(($f)(y))
+    for (fu, un) in ((:rad2deg, "degrees"),)
+        name = string(fd)
+        @eval begin
+            @doc """
+                $($name)(x)
+
+            Compute the inverse $($fn) of `x`, where the output is in $($un).
+            If `x` is a matrix, `x` needs to be a square matrix. """ ($fd)(x) = ($fu).(($f)(x))
+        end
     end
 end
 
@@ -1294,5 +1302,5 @@ end
 
 Compute the inverse tangent of `y` or `y/x`, respectively, where the output is in degrees.
 """
-atand(y)    = rad2deg(atan(y))
-atand(y, x) = rad2deg(atan(y,x))
+atand(y)    = rad2deg.(atan(y))
+atand(y, x) = rad2deg.(atan(y,x))

test/math.jl

@@ -341,6 +341,35 @@ end
     @test Array(acosh.(STAA)) == acosh.(TAA)
     @test Array(acsch.(STAA)) == acsch.(TAA)
     @test Array(acoth.(STAA)) == acoth.(TAA)
+    @test sind(TAA) == sin(deg2rad.(TAA))
+    @test cosd(TAA) == cos(deg2rad.(TAA))
+    @test tand(TAA) == tan(deg2rad.(TAA))
+    @test asind(TAA) == rad2deg.(asin(TAA))
+    @test acosd(TAA) == rad2deg.(acos(TAA))
+    @test atand(TAA) == rad2deg.(atan(TAA))
+    @test asecd(TAA) == rad2deg.(asec(TAA))
+    @test acscd(TAA) == rad2deg.(acsc(TAA))
+    @test acotd(TAA) == rad2deg.(acot(TAA))
+
+    m = rand(3,2) # not square matrix
+    ex = @test_throws DimensionMismatch sind(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch cosd(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch tand(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch asind(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch acosd(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch atand(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch asecd(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch acscd(m)
+    @test startswith(ex.value.msg, "matrix is not square")
+    ex = @test_throws DimensionMismatch acotd(m)
+    @test startswith(ex.value.msg, "matrix is not square")
 end
 
 @testset "check exp2(::Integer) matches exp2(::Float)" begin