matrix.hpp

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#pragma once
#include <vector>
#include "wiring.h"
#include "stdexcept"
 
class Matrix
{
public:
  Matrix() = default;
  ~Matrix() = default;
 
  Matrix(size_t rows, size_t cols)
  : mRows(rows),
    mCols(cols),
    mData(rows * cols)
  {}
 
  Matrix(size_t rows, size_t cols, std::vector<float> data)
  : mRows(rows),
    mCols(cols),
    mData(data)
  {}
 
  float & operator()(size_t i, size_t j)
  {
    return mData.at(i * mCols + j);
  }
 
  float operator()(size_t i, size_t j) const
  {
    return mData.at(i * mCols + j);
  }
 
  Matrix transpose() const
  {
    auto M_T = Matrix{mCols, mRows};
    for (size_t i = 0; i < mRows; ++i) {
      for (size_t j = 0; j < mCols; ++j) {
        M_T(j, i) = mData.at(i * mCols + j);
      }
    }
    return M_T;
  }
 
  Matrix T() const
  {
    return transpose();
  }
 
  std::vector<float> operator*(const std::vector<float> & v) const
  {
    if (v.size() != mCols) {
      Serial.println("Matrix multiplication error: vector size does not match matrix columns");
      return {};
    }
    std::vector<float> v_(mRows);
    for (size_t i = 0; i < mRows; ++i) {
      auto sum = 0.f;
      for (size_t j = 0; j < mCols; ++j) {
        sum += v.at(j) * mData.at(i * mCols + j);
      }
      v_.at(i) = sum;
    }
    return v_;
  }
 
  std::vector<float> getData() const
  {
    return mData;
  }
 
  bool operator==(const Matrix & rhs) const
  {
    return mData == rhs.getData();
  }
 
private:
 
  size_t mRows;
  size_t mCols;
  std::vector<float> mData;
};