.. SPDX-FileCopyrightText: 2019-2020 Intel Corporation .. .. SPDX-License-Identifier: CC-BY-4.0 .. _onemkl_vm_lgamma: lgamma ====== .. container:: Computes the natural logarithm of the absolute value of gamma function for vector elements. .. container:: section .. rubric:: Syntax :class: sectiontitle Buffer API: .. code-block:: cpp namespace oneapi::mkl::vm { sycl::event lgamma( sycl::queue& exec_queue, std::int64_t n, sycl::buffer& a, sycl::buffer& y, oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined, oneapi::mkl::vm::error_handler errhandler = {}); } // namespace oneapi::mkl::vm USM API: .. code-block:: cpp namespace oneapi::mkl::vm { sycl::event lgamma( sycl::queue& exec_queue, std::int64_t n, const T *a, T* y, std::vector const & depends = {}, oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined, oneapi::mkl::vm::error_handler errhandler = {}); } // namespace oneapi::mkl::vm ``lgamma`` supports the following precisions. .. list-table:: :header-rows: 1 * - T * - ``float`` * - ``double`` .. container:: section .. rubric:: Description :class: sectiontitle The lgamma(a) function computes the natural logarithm of the absolute value of gamma function for elements of the input vector ``a`` and writes them to the output vector ``y``. Precision overflow thresholds for the lgamma function are beyond the scope of this document. If the result does not meet the target precision, the function sets the VM status code to ``oneapi::mkl::vm::status::overflow``. .. container:: tablenoborder .. list-table:: :header-rows: 1 * - Argument - Result - VM status code * - +1 - +0 -   * - +2 - +0 -   * - +0 - +∞ - ``oneapi::mkl::vm::status::sing`` * - -0 - +∞ - ``oneapi::mkl::vm::status::sing`` * - negative integer - +∞ - ``oneapi::mkl::vm::status::sing`` * - -∞ - +∞ -   * - +∞ - +∞ -   * - a > overflow - +∞ - ``oneapi::mkl::vm::status::overflow`` * - QNAN - QNAN -   * - SNAN - QNAN -   .. container:: section .. rubric:: Input Parameters :class: sectiontitle Buffer API: exec_queue The queue where the routine should be executed. n Specifies the number of elements to be calculated. a The buffer ``a`` containing input vector of size ``n``. mode Overrides the global VM mode setting for this function call. See :ref:`onemkl_vm_setmode` function for possible values and their description. This is an optional parameter. The default value is ``oneapi::mkl::vm::mode::not_defined``. errhandler Sets local error handling mode for this function call. See the :ref:`onemkl_vm_create_error_handler` function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default. USM API: exec_queue The queue where the routine should be executed. n Specifies the number of elements to be calculated. a Pointer ``a`` to the input vector of size ``n``. depends Vector of dependent events (to wait for input data to be ready). mode Overrides the global VM mode setting for this function call. See the :ref:`onemkl_vm_setmode` function for possible values and their description. This is an optional parameter. The default value is ``oneapi::mkl::vm::mode::not_defined``. errhandler Sets local error handling mode for this function call. See the :ref:`onemkl_vm_create_error_handler` function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default. .. container:: section .. rubric:: Output Parameters :class: sectiontitle Buffer API: y The buffer ``y`` containing the output vector of size ``n``. USM API: y Pointer ``y`` to the output vector of size ``n``. return value (event) Event, signifying availability of computed output and status code(s). .. container:: section .. rubric:: Exceptions :class: sectiontitle For list of generated exceptions please refer to  :ref:`onemkl_vm_exceptions` .. container:: familylinks .. container:: parentlink **Parent topic:** :ref:`onemkl_vm_mathematical_functions`