1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2020 ARM Limited. All rights reserved.
3 *
4 * $Date: 23. March 2020
5 * $Revision: V1.7.0
6 *
7 * Project: CMSIS DSP Library
8 * Title: arm_linear_interp_example_f32.c
9 *
10 * Description: Example code demonstrating usage of sin function
11 * and uses linear interpolation to get higher precision
12 *
13 * Target Processor: Cortex-M55/Cortex-M7/Cortex-M4/Cortex-M3/Cortex-M0
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * - Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * - Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in
22 * the documentation and/or other materials provided with the
23 * distribution.
24 * - Neither the name of ARM LIMITED nor the names of its contributors
25 * may be used to endorse or promote products derived from this
26 * software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
31 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
32 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
33 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
34 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
35 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
36 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
38 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
39 * POSSIBILITY OF SUCH DAMAGE.
40 * -------------------------------------------------------------------- */
41
42
43 /**
44 * @addtogroup groupExamples
45 * @{
46 *
47 * @defgroup LinearInterpExample Linear Interpolate Example
48 *
49 * <b> CMSIS DSP Software Library -- Linear Interpolate Example </b>
50 *
51 * <b> Description </b>
52 * This example demonstrates usage of linear interpolate modules and fast math modules.
53 * Method 1 uses fast math sine function to calculate sine values using cubic interpolation and method 2 uses
54 * linear interpolation function and results are compared to reference output.
55 * Example shows linear interpolation function can be used to get higher precision compared to fast math sin calculation.
56 *
57 * \par Block Diagram:
58 * \par
59 * \image html linearInterpExampleMethod1.gif "Method 1: Sine caluclation using fast math"
60 * \par
61 * \image html linearInterpExampleMethod2.gif "Method 2: Sine caluclation using interpolation function"
62 *
63 * \par Variables Description:
64 * \par
65 * \li \c testInputSin_f32 points to the input values for sine calculation
66 * \li \c testRefSinOutput32_f32 points to the reference values caculated from sin() matlab function
67 * \li \c testOutput points to output buffer calculation from cubic interpolation
68 * \li \c testLinIntOutput points to output buffer calculation from linear interpolation
69 * \li \c snr1 Signal to noise ratio for reference and cubic interpolation output
70 * \li \c snr2 Signal to noise ratio for reference and linear interpolation output
71 *
72 * \par CMSIS DSP Software Library Functions Used:
73 * \par
74 * - arm_sin_f32()
75 * - arm_linear_interp_f32()
76 *
77 * <b> Refer </b>
78 * \link arm_linear_interp_example_f32.c \endlink
79 *
80 * \example arm_linear_interp_example_f32.c
81 *
82 * @} */
83
84 #include "arm_math.h"
85 #include "math_helper.h"
86
87 #if defined(SEMIHOSTING)
88 #include <stdio.h>
89 #endif
90
91 #define SNR_THRESHOLD 90
92 #define TEST_LENGTH_SAMPLES 10
93 #define XSPACING (0.005f)
94
95 /* ----------------------------------------------------------------------
96 * Test input data for F32 SIN function
97 * Generated by the MATLAB rand() function
98 * randn('state', 0)
99 * xi = (((1/4.18318581819710)* randn(blockSize, 1) * 2* pi));
100 * --------------------------------------------------------------------*/
101 float32_t testInputSin_f32[TEST_LENGTH_SAMPLES] =
102 {
103 -0.649716504673081170, -2.501723745497831200,
104 0.188250329003310100, 0.432092748487532540,
105 -1.722010988459680800, 1.788766476323060600,
106 1.786136060975809500, -0.056525543169408797,
107 0.491596272728153760, 0.262309671126153390
108 };
109
110 /*------------------------------------------------------------------------------
111 * Reference out of SIN F32 function for Block Size = 10
112 * Calculated from sin(testInputSin_f32)
113 *------------------------------------------------------------------------------*/
114 float32_t testRefSinOutput32_f32[TEST_LENGTH_SAMPLES] =
115 {
116 -0.604960695383043530, -0.597090287967934840,
117 0.187140422442966500, 0.418772124875992690,
118 -0.988588831792106880, 0.976338412038794010,
119 0.976903856413481100, -0.056495446835214236,
120 0.472033731854734240, 0.259311907228582830
121 };
122
123 /*------------------------------------------------------------------------------
124 * Method 1: Test out Buffer Calculated from Cubic Interpolation
125 *------------------------------------------------------------------------------*/
126 float32_t testOutput[TEST_LENGTH_SAMPLES];
127
128 /*------------------------------------------------------------------------------
129 * Method 2: Test out buffer Calculated from Linear Interpolation
130 *------------------------------------------------------------------------------*/
131 float32_t testLinIntOutput[TEST_LENGTH_SAMPLES];
132
133 /*------------------------------------------------------------------------------
134 * External table used for linear interpolation
135 *------------------------------------------------------------------------------*/
136 extern const float arm_linear_interep_table[1884];
137
138 /* ----------------------------------------------------------------------
139 * Global Variables for caluclating SNR's for Method1 & Method 2
140 * ------------------------------------------------------------------- */
141 float32_t snr1;
142 float32_t snr2;
143
144 /* ----------------------------------------------------------------------------
145 * Calculation of Sine values from Cubic Interpolation and Linear interpolation
146 * ---------------------------------------------------------------------------- */
main(void)147 int32_t main(void)
148 {
149 uint32_t i;
150 arm_status status;
151
152 arm_linear_interp_instance_f32 S = {1884, -3.141592653589793238, XSPACING, (float*)&arm_linear_interep_table[0]};
153
154 /*------------------------------------------------------------------------------
155 * Method 1: Test out Calculated from Cubic Interpolation
156 *------------------------------------------------------------------------------*/
157 for(i=0; i< TEST_LENGTH_SAMPLES; i++)
158 {
159 testOutput[i] = arm_sin_f32(testInputSin_f32[i]);
160 }
161
162 /*------------------------------------------------------------------------------
163 * Method 2: Test out Calculated from Cubic Interpolation and Linear interpolation
164 *------------------------------------------------------------------------------*/
165
166 for(i=0; i< TEST_LENGTH_SAMPLES; i++)
167 {
168 testLinIntOutput[i] = arm_linear_interp_f32(&S, testInputSin_f32[i]);
169 }
170
171 /*------------------------------------------------------------------------------
172 * SNR calculation for method 1
173 *------------------------------------------------------------------------------*/
174 snr1 = arm_snr_f32(testRefSinOutput32_f32, testOutput, 2);
175
176 /*------------------------------------------------------------------------------
177 * SNR calculation for method 2
178 *------------------------------------------------------------------------------*/
179 snr2 = arm_snr_f32(testRefSinOutput32_f32, testLinIntOutput, 2);
180
181 /*------------------------------------------------------------------------------
182 * Initialise status depending on SNR calculations
183 *------------------------------------------------------------------------------*/
184 status = (snr2 <= snr1) ? ARM_MATH_TEST_FAILURE : ARM_MATH_SUCCESS;
185
186 if (status != ARM_MATH_SUCCESS)
187 {
188 #if defined (SEMIHOSTING)
189 printf("FAILURE\n");
190 #else
191 while (1); /* main function does not return */
192 #endif
193 }
194 else
195 {
196 #if defined (SEMIHOSTING)
197 printf("SUCCESS\n");
198 #else
199 while (1); /* main function does not return */
200 #endif
201 }
202
203 }
204
205 /** \endlink */
206
