/* ----------------------------------------------------------------------
* Copyright (C) 2010-2012 ARM Limited. All rights reserved.
*
* $Date:         17. January 2013
* $Revision:     V1.4.0
*
* Project:       CMSIS DSP Library
* Title:         arm_matrix_example_f32.c
*
* Description:   Example code demonstrating least square fit to data
*                using matrix functions
*
* 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 MatrixExample Matrix Example
 *
 * \par Description:
 * \par
 * Demonstrates the use of Matrix Transpose, Matrix Muliplication, and Matrix Inverse
 * functions to apply least squares fitting to input data. Least squares fitting is
 * the procedure for finding the best-fitting curve that minimizes the sum of the
 * squares of the offsets (least square error) from a given set of data.
 *
 * \par Algorithm:
 * \par
 * The linear combination of parameters considered is as follows:
 * \par
 * <code>A * X = B</code>, where \c X is the unknown value and can be estimated
 * from \c A & \c B.
 * \par
 * The least squares estimate \c X is given by the following equation:
 * \par
 * <code>X = Inverse(A<sup>T</sup> * A) *  A<sup>T</sup> * B</code>
 *
 * \par Block Diagram:
 * \par
 * \image html matrixExample.gif
 *
 * \par Variables Description:
 * \par
 * \li \c A_f32 input matrix in the linear combination equation
 * \li \c B_f32 output matrix in the linear combination equation
 * \li \c X_f32 unknown matrix estimated using \c A_f32 & \c B_f32 matrices
 *
 * \par CMSIS DSP Software Library Functions Used:
 * \par
 * - arm_mat_init_f32()
 * - arm_mat_trans_f32()
 * - arm_mat_mult_f32()
 * - arm_mat_inverse_f32()
 *
 * <b> Refer  </b>
 * \link arm_matrix_example_f32.c \endlink
 *
 */


/** \example arm_matrix_example_f32.c
  */

#include "arm_math.h"
#include "math_helper.h"

#define SNR_THRESHOLD   90

/* --------------------------------------------------------------------------------
* Test input data(Cycles) taken from FIR Q15 module for differant cases of blockSize
* and tapSize
* --------------------------------------------------------------------------------- */

const float32_t B_f32[4] =
{
  782.0, 7577.0, 470.0, 4505.0
};

/* --------------------------------------------------------------------------------
* Formula to fit is  C1 + C2 * numTaps + C3 * blockSize + C4 * numTaps * blockSize
* -------------------------------------------------------------------------------- */

const float32_t A_f32[16] =
{
  /* Const,   numTaps,   blockSize,   numTaps*blockSize */
  1.0,     32.0,      4.0,     128.0,
  1.0,     32.0,     64.0,    2048.0,
  1.0,     16.0,      4.0,      64.0,
  1.0,     16.0,     64.0,    1024.0,
};


/* ----------------------------------------------------------------------
* Temporary buffers  for storing intermediate values
* ------------------------------------------------------------------- */
/* Transpose of A Buffer */
float32_t AT_f32[16];
/* (Transpose of A * A) Buffer */
float32_t ATMA_f32[16];
/* Inverse(Transpose of A * A)  Buffer */
float32_t ATMAI_f32[16];
/* Test Output Buffer */
float32_t X_f32[4];

/* ----------------------------------------------------------------------
* Reference ouput buffer C1, C2, C3 and C4 taken from MATLAB
* ------------------------------------------------------------------- */
const float32_t xRef_f32[4] = {73.0, 8.0, 21.25, 2.875};

float32_t snr;


/* ----------------------------------------------------------------------
* Max magnitude FFT Bin test
* ------------------------------------------------------------------- */

int32_t main(void)
{

  arm_matrix_instance_f32 A;      /* Matrix A Instance */
  arm_matrix_instance_f32 AT;     /* Matrix AT(A transpose) instance */
  arm_matrix_instance_f32 ATMA;   /* Matrix ATMA( AT multiply with A) instance */
  arm_matrix_instance_f32 ATMAI;  /* Matrix ATMAI(Inverse of ATMA) instance */
  arm_matrix_instance_f32 B;      /* Matrix B instance */
  arm_matrix_instance_f32 X;      /* Matrix X(Unknown Matrix) instance */

  uint32_t srcRows, srcColumns;  /* Temporary variables */
  arm_status status;

  /* Initialise A Matrix Instance with numRows, numCols and data array(A_f32) */
  srcRows = 4;
  srcColumns = 4;
  arm_mat_init_f32(&A, srcRows, srcColumns, (float32_t *)A_f32);

  /* Initialise Matrix Instance AT with numRows, numCols and data array(AT_f32) */
  srcRows = 4;
  srcColumns = 4;
  arm_mat_init_f32(&AT, srcRows, srcColumns, AT_f32);

  /* calculation of A transpose */
  status = arm_mat_trans_f32(&A, &AT);


  /* Initialise ATMA Matrix Instance with numRows, numCols and data array(ATMA_f32) */
  srcRows = 4;
  srcColumns = 4;
  arm_mat_init_f32(&ATMA, srcRows, srcColumns, ATMA_f32);

  /* calculation of AT Multiply with A */
  status = arm_mat_mult_f32(&AT, &A, &ATMA);

  /* Initialise ATMAI Matrix Instance with numRows, numCols and data array(ATMAI_f32) */
  srcRows = 4;
  srcColumns = 4;
  arm_mat_init_f32(&ATMAI, srcRows, srcColumns, ATMAI_f32);

  /* calculation of Inverse((Transpose(A) * A) */
  status = arm_mat_inverse_f32(&ATMA, &ATMAI);

  /* calculation of (Inverse((Transpose(A) * A)) *  Transpose(A)) */
  status = arm_mat_mult_f32(&ATMAI, &AT, &ATMA);

  /* Initialise B Matrix Instance with numRows, numCols and data array(B_f32) */
  srcRows = 4;
  srcColumns = 1;
  arm_mat_init_f32(&B, srcRows, srcColumns, (float32_t *)B_f32);

  /* Initialise X Matrix Instance with numRows, numCols and data array(X_f32) */
  srcRows = 4;
  srcColumns = 1;
  arm_mat_init_f32(&X, srcRows, srcColumns, X_f32);

  /* calculation ((Inverse((Transpose(A) * A)) *  Transpose(A)) * B) */
  status = arm_mat_mult_f32(&ATMA, &B, &X);

  /* Comparison of reference with test output */
  snr = arm_snr_f32((float32_t *)xRef_f32, X_f32, 4);

  /*------------------------------------------------------------------------------
  *            Initialise status depending on SNR calculations
  *------------------------------------------------------------------------------*/
  if ( snr > SNR_THRESHOLD)
  {
    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 */
