| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010-2012 ARM Limited. All rights reserved. |
| * |
| * $Date: 17. January 2013 |
| * $Revision: V1.4.0 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_linear_interp_example_f32.c |
| * |
| * Description: Example code demonstrating usage of sin function |
| * and uses linear interpolation to get higher precision |
| * |
| * Target Processor: Cortex-M4/Cortex-M3 |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * - Neither the name of ARM LIMITED nor the names of its contributors |
| * may be used to endorse or promote products derived from this |
| * software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| * -------------------------------------------------------------------- */ |
| |
| |
| /** |
| * @ingroup groupExamples |
| */ |
| |
| /** |
| * @defgroup LinearInterpExample Linear Interpolate Example |
| * |
| * <b> CMSIS DSP Software Library -- Linear Interpolate Example </b> |
| * |
| * <b> Description </b> |
| * This example demonstrates usage of linear interpolate modules and fast math modules. |
| * Method 1 uses fast math sine function to calculate sine values using cubic interpolation and method 2 uses |
| * linear interpolation function and results are compared to reference output. |
| * Example shows linear interpolation function can be used to get higher precision compared to fast math sin calculation. |
| * |
| * \par Block Diagram: |
| * \par |
| * \image html linearInterpExampleMethod1.gif "Method 1: Sine caluclation using fast math" |
| * \par |
| * \image html linearInterpExampleMethod2.gif "Method 2: Sine caluclation using interpolation function" |
| * |
| * \par Variables Description: |
| * \par |
| * \li \c testInputSin_f32 points to the input values for sine calculation |
| * \li \c testRefSinOutput32_f32 points to the reference values caculated from sin() matlab function |
| * \li \c testOutput points to output buffer calculation from cubic interpolation |
| * \li \c testLinIntOutput points to output buffer calculation from linear interpolation |
| * \li \c snr1 Signal to noise ratio for reference and cubic interpolation output |
| * \li \c snr2 Signal to noise ratio for reference and linear interpolation output |
| * |
| * \par CMSIS DSP Software Library Functions Used: |
| * \par |
| * - arm_sin_f32() |
| * - arm_linear_interp_f32() |
| * |
| * <b> Refer </b> |
| * \link arm_linear_interp_example_f32.c \endlink |
| * |
| */ |
| |
| |
| /** \example arm_linear_interp_example_f32.c |
| */ |
| |
| #include "arm_math.h" |
| #include "math_helper.h" |
| |
| #define SNR_THRESHOLD 90 |
| #define TEST_LENGTH_SAMPLES 10 |
| #define XSPACING (0.00005f) |
| |
| /* ---------------------------------------------------------------------- |
| * Test input data for F32 SIN function |
| * Generated by the MATLAB rand() function |
| * randn('state', 0) |
| * xi = (((1/4.18318581819710)* randn(blockSize, 1) * 2* pi)); |
| * --------------------------------------------------------------------*/ |
| float32_t testInputSin_f32[TEST_LENGTH_SAMPLES] = |
| { |
| -0.649716504673081170, -2.501723745497831200, |
| 0.188250329003310100, 0.432092748487532540, |
| -1.722010988459680800, 1.788766476323060600, |
| 1.786136060975809500, -0.056525543169408797, |
| 0.491596272728153760, 0.262309671126153390 |
| }; |
| |
| /*------------------------------------------------------------------------------ |
| * Reference out of SIN F32 function for Block Size = 10 |
| * Calculated from sin(testInputSin_f32) |
| *------------------------------------------------------------------------------*/ |
| float32_t testRefSinOutput32_f32[TEST_LENGTH_SAMPLES] = |
| { |
| -0.604960695383043530, -0.597090287967934840, |
| 0.187140422442966500, 0.418772124875992690, |
| -0.988588831792106880, 0.976338412038794010, |
| 0.976903856413481100, -0.056495446835214236, |
| 0.472033731854734240, 0.259311907228582830 |
| }; |
| |
| /*------------------------------------------------------------------------------ |
| * Method 1: Test out Buffer Calculated from Cubic Interpolation |
| *------------------------------------------------------------------------------*/ |
| float32_t testOutput[TEST_LENGTH_SAMPLES]; |
| |
| /*------------------------------------------------------------------------------ |
| * Method 2: Test out buffer Calculated from Linear Interpolation |
| *------------------------------------------------------------------------------*/ |
| float32_t testLinIntOutput[TEST_LENGTH_SAMPLES]; |
| |
| /*------------------------------------------------------------------------------ |
| * External table used for linear interpolation |
| *------------------------------------------------------------------------------*/ |
| extern float arm_linear_interep_table[188495]; |
| |
| /* ---------------------------------------------------------------------- |
| * Global Variables for caluclating SNR's for Method1 & Method 2 |
| * ------------------------------------------------------------------- */ |
| float32_t snr1; |
| float32_t snr2; |
| |
| /* ---------------------------------------------------------------------------- |
| * Calculation of Sine values from Cubic Interpolation and Linear interpolation |
| * ---------------------------------------------------------------------------- */ |
| int32_t main(void) |
| { |
| uint32_t i; |
| arm_status status; |
| |
| arm_linear_interp_instance_f32 S = {188495, -3.141592653589793238, XSPACING, &arm_linear_interep_table[0]}; |
| |
| /*------------------------------------------------------------------------------ |
| * Method 1: Test out Calculated from Cubic Interpolation |
| *------------------------------------------------------------------------------*/ |
| for(i=0; i< TEST_LENGTH_SAMPLES; i++) |
| { |
| testOutput[i] = arm_sin_f32(testInputSin_f32[i]); |
| } |
| |
| /*------------------------------------------------------------------------------ |
| * Method 2: Test out Calculated from Cubic Interpolation and Linear interpolation |
| *------------------------------------------------------------------------------*/ |
| |
| for(i=0; i< TEST_LENGTH_SAMPLES; i++) |
| { |
| testLinIntOutput[i] = arm_linear_interp_f32(&S, testInputSin_f32[i]); |
| } |
| |
| /*------------------------------------------------------------------------------ |
| * SNR calculation for method 1 |
| *------------------------------------------------------------------------------*/ |
| snr1 = arm_snr_f32(testRefSinOutput32_f32, testOutput, 2); |
| |
| /*------------------------------------------------------------------------------ |
| * SNR calculation for method 2 |
| *------------------------------------------------------------------------------*/ |
| snr2 = arm_snr_f32(testRefSinOutput32_f32, testLinIntOutput, 2); |
| |
| /*------------------------------------------------------------------------------ |
| * Initialise status depending on SNR calculations |
| *------------------------------------------------------------------------------*/ |
| if ( snr2 > snr1) |
| { |
| status = ARM_MATH_SUCCESS; |
| } |
| else |
| { |
| status = ARM_MATH_TEST_FAILURE; |
| } |
| |
| /* ---------------------------------------------------------------------- |
| ** Loop here if the signals fail the PASS check. |
| ** This denotes a test failure |
| ** ------------------------------------------------------------------- */ |
| if ( status != ARM_MATH_SUCCESS) |
| { |
| while (1); |
| } |
| |
| while (1); /* main function does not return */ |
| } |
| |
| /** \endlink */ |
