diff --git a/.gitignore b/.gitignore index 73e203a64..86bab2717 100644 --- a/.gitignore +++ b/.gitignore @@ -30,3 +30,4 @@ node_modules/ __pycache__/ *.pyc spec/**/generated +tmp/ \ No newline at end of file diff --git a/spec/API_specification/array_api/elementwise_functions.py b/spec/API_specification/array_api/elementwise_functions.py index 7acefaf52..4e26ee797 100644 --- a/spec/API_specification/array_api/elementwise_functions.py +++ b/spec/API_specification/array_api/elementwise_functions.py @@ -1236,12 +1236,20 @@ def sin(x: array, /) -> array: """ def sinh(x: array, /) -> array: - """ - Calculates an implementation-dependent approximation to the hyperbolic sine, having domain ``[-infinity, +infinity]`` and codomain ``[-infinity, +infinity]``, for each element ``x_i`` of the input array ``x``. + r""" + Calculates an implementation-dependent approximation to the hyperbolic sine for each element ``x_i`` of the input array ``x``. + + The mathematical definition of the hyperbolic sine is + + .. math:: + \operatorname{sinh}(x) = \frac{e^x - e^{-x}}{2} **Special cases** - For floating-point operands, + .. note:: + For all operands, ``sinh(x)`` must equal ``-sinh(-x)``. + + For real-valued floating-point operands, - If ``x_i`` is ``NaN``, the result is ``NaN``. - If ``x_i`` is ``+0``, the result is ``+0``. @@ -1249,15 +1257,38 @@ def sinh(x: array, /) -> array: - If ``x_i`` is ``+infinity``, the result is ``+infinity``. - If ``x_i`` is ``-infinity``, the result is ``-infinity``. + For complex floating-point operands, let ``a = real(x_i)``, ``b = imag(x_i)``, and + + .. note:: + For complex floating-point operands, ``sinh(conj(x))`` must equal ``conj(sinh(x))``. + + - If ``a`` is ``+0`` and ``b`` is ``+0``, the result is ``+0 + 0j``. + - If ``a`` is ``+0`` and ``b`` is ``+infinity``, the result is ``0 + NaN j`` (sign of the real component is unspecified). + - If ``a`` is ``+0`` and ``b`` is ``NaN``, the result is ``0 + NaN j`` (sign of the real component is unspecified). + - If ``a`` is a positive (i.e., greater than ``0``) finite number and ``b`` is ``+infinity``, the result is ``NaN + NaN j``. + - If ``a`` is a positive (i.e., greater than ``0``) finite number and ``b`` is ``NaN``, the result is ``NaN + NaN j``. + - If ``a`` is ``+infinity`` and ``b`` is ``+0``, the result is ``+infinity + 0j``. + - If ``a`` is ``+infinity`` and ``b`` is a positive finite number, the result is ``+infinity * cis(b)``. + - If ``a`` is ``+infinity`` and ``b`` is ``+infinity``, the result is ``infinity + NaN j`` (sign of the real component is unspecified). + - If ``a`` is ``+infinity`` and ``b`` is ``NaN``, the result is ``infinity + NaN j`` (sign of the real component is unspecified). + - If ``a`` is ``NaN`` and ``b`` is ``+0``, the result is ``NaN + 0j``. + - If ``a`` is ``NaN`` and ``b`` is a nonzero finite number, the result is ``NaN + NaN j``. + - If ``a`` is ``NaN`` and ``b`` is ``NaN``, the result is ``NaN + NaN j``. + + where ``cis(v)`` is ``cos(v) + sin(v)*1j``. + + .. note:: + The hyperbolic sine is an entire function in the complex plane and has no branch cuts. The function is periodic, with period :math:`2\pi j`, with respect to the imaginary component. + Parameters ---------- x: array - input array whose elements each represent a hyperbolic angle. Should have a real-valued floating-point data type. + input array whose elements each represent a hyperbolic angle. Should have a floating-point data type. Returns ------- out: array - an array containing the hyperbolic sine of each element in ``x``. The returned array must have a real-valued floating-point data type determined by :ref:`type-promotion`. + an array containing the hyperbolic sine of each element in ``x``. The returned array must have a floating-point data type determined by :ref:`type-promotion`. """ def square(x: array, /) -> array: