Beispiel #1
0
  /** Compute y <- alpha*op(a)*x + beta * y (general matrix vector multiplication) */
  public static FloatMatrix gemv(
      float alpha, FloatMatrix a, FloatMatrix x, float beta, FloatMatrix y) {
    if (false) {
      NativeBlas.sgemv(
          'N', a.rows, a.columns, alpha, a.data, 0, a.rows, x.data, 0, 1, beta, y.data, 0, 1);
    } else {
      if (beta == 0.0f) {
        for (int i = 0; i < y.length; i++) y.data[i] = 0.0f;

        for (int j = 0; j < a.columns; j++) {
          float xj = x.get(j);
          if (xj != 0.0f) {
            for (int i = 0; i < a.rows; i++) y.data[i] += a.get(i, j) * xj;
          }
        }
      } else {
        for (int j = 0; j < a.columns; j++) {
          float byj = beta * y.data[j];
          float xj = x.get(j);
          for (int i = 0; i < a.rows; i++) y.data[j] = a.get(i, j) * xj + byj;
        }
      }
    }
    return y;
  }
  public static FloatMatrix conv2d(FloatMatrix input, FloatMatrix kernel, Type type) {

    FloatMatrix xShape = new FloatMatrix(1, 2);
    xShape.put(0, input.rows);
    xShape.put(1, input.columns);

    FloatMatrix yShape = new FloatMatrix(1, 2);
    yShape.put(0, kernel.rows);
    yShape.put(1, kernel.columns);

    FloatMatrix zShape = xShape.add(yShape).sub(1);
    int retRows = (int) zShape.get(0);
    int retCols = (int) zShape.get(1);

    ComplexFloatMatrix fftInput = complexDisceteFourierTransform(input, retRows, retCols);
    ComplexFloatMatrix fftKernel = complexDisceteFourierTransform(kernel, retRows, retCols);
    ComplexFloatMatrix mul = fftKernel.mul(fftInput);
    ComplexFloatMatrix retComplex = complexInverseDisceteFourierTransform(mul);

    FloatMatrix ret = retComplex.getReal();

    if (type == Type.VALID) {

      FloatMatrix validShape = xShape.subi(yShape).add(1);

      FloatMatrix start = zShape.sub(validShape).div(2);
      FloatMatrix end = start.add(validShape);
      if (start.get(0) < 1 || start.get(1) < 1)
        throw new IllegalStateException("Illegal row index " + start);
      if (end.get(0) < 1 || end.get(1) < 1)
        throw new IllegalStateException("Illegal column index " + end);

      ret =
          ret.get(
              RangeUtils.interval((int) start.get(0), (int) end.get(0)),
              RangeUtils.interval((int) start.get(1), (int) end.get(1)));
    }

    return ret;
  }