Module: Numo::FFTW

Defined in:
ext/numo/fftw/fftw.c

Class Method Summary collapse

Class Method Details

.dft(narray, sign) ⇒ Numo::DComplex

Multi-dimentional Complex Discrete Fourier Transform

Parameters:

  • narray (Numo::DComplex) —

    Input NArray with any dimension.

  • sign (Numeric) —

    the sign of the exponent in the formula that defines the Fourier transform. It can be -1 (= FFTW_FORWARD) or +1 (= FFTW_BACKWARD).

Returns:

  • (Numo::DComplex) —

    Result DComplex NArray with the same shape as input NArray.



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# File 'ext/numo/fftw/fftw.c', line 232

static VALUE
numo_fftw_dft(VALUE mod, VALUE vna, VALUE vsign)
{
    VALUE vans;
    int sign;
    narray_t *na;
    int ndim, i;
    int *shape;
    fftw_complex *in, *out;
    fftw_plan plan;

    sign = NUM2INT(vsign);
    if (sign != 1 && sign != -1) {
        rb_raise(rb_eArgError,"second argument (sign) must be 1 or -1");
    }
    if (CLASS_OF(vna) != numo_cDComplex) {
        vna = rb_funcall(numo_cDComplex, id_cast, 1, vna);
    }
    if (!RTEST(nary_check_contiguous(vna))) {
        vna = nary_dup(vna);
    }
    GetNArray(vna,na);
    ndim = NA_NDIM(na);
    shape = ALLOCA_N(int,ndim);
    for (i=0; i<ndim; i++) {
        shape[i] = NA_SHAPE(na)[i];
    }
    if (TEST_INPLACE(vna)) {
        vans = vna;
        in = out = (fftw_complex*)na_get_pointer_for_read_write(vna);
    } else {
        vans = nary_s_new_like(numo_cDComplex, vna);
        in = (fftw_complex*)na_get_pointer_for_read(vna);
        out = (fftw_complex*)na_get_pointer_for_write(vans);
    }
    plan = fftw_plan_dft(ndim, shape, in, out, sign, FFTW_ESTIMATE);
    fftw_execute(plan);
    fftw_destroy_plan(plan);

    RB_GC_GUARD(vna);
    return vans;
}

.dft_1d(narray, sign) ⇒ Numo::DComplex

1-dimentional Complex Discrete Fourier Transform along the last 1 dimension.

Parameters:

  • narray (Numo::DComplex) —

    Input NArray with at least 1 dimension.

  • sign (Numeric) —

    the sign of the exponent in the formula that defines the Fourier transform. It can be -1 (= FFTW_FORWARD) or +1 (= FFTW_BACKWARD).

Returns:

  • (Numo::DComplex) —

    Result DComplex NArray with shape = [.., nx].



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# File 'ext/numo/fftw/fftw.c', line 55

static VALUE
numo_fftw_dft_1d(VALUE mod, VALUE vna, VALUE vsign)
{
    narray_t *na;
    VALUE vans;
    int ndim;
    int sign=-1;
    size_t shape[1];
    ndfunc_arg_in_t ain[1] = {{cDC,1}};
    ndfunc_arg_out_t aout[1] = {{cDC,1,shape}};
    ndfunc_t ndf = { iter_fftw_dft_1d, NO_LOOP|NDF_INPLACE, 1, 1, ain, aout };

    sign = NUM2INT(vsign);
    if (sign != 1 && sign != -1) {
        rb_raise(rb_eArgError,"second argument (sign) must be 1 or -1");
    }
    GetNArray(vna,na);
    ndim = NA_NDIM(na);
    if (ndim<1) {
        rb_raise(nary_eDimensionError,"ndim(=%d) should >= 1",ndim);
    }

    shape[0] = NA_SHAPE(na)[ndim-1];

    vans = na_ndloop3(&ndf, &sign, 1, vna);
    RB_GC_GUARD(vna);
    return vans;
}

.dft_2d(narray, sign) ⇒ Numo::DComplex

2-dimentional Complex Discrete Fourier Transform along the last 2 dimensions.

Parameters:

  • narray (Numo::DComplex) —

    Input NArray with at least 2 dimensions.

  • sign (Numeric) —

    the sign of the exponent in the formula that defines the Fourier transform. It can be -1 (= FFTW_FORWARD) or +1 (= FFTW_BACKWARD).

Returns:

  • (Numo::DComplex) —

    Result DComplex NArray with shape = [.., ny, nx].



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# File 'ext/numo/fftw/fftw.c', line 119

static VALUE
numo_fftw_dft_2d(VALUE mod, VALUE vna, VALUE vsign)
{
    narray_t *na;
    VALUE vans;
    int ndim;
    int sign=-1;
    size_t shape[2];
    ndfunc_arg_in_t ain[1] = {{cDC,2}};
    ndfunc_arg_out_t aout[1] = {{cDC,2,shape}};
    ndfunc_t ndf = { iter_fftw_dft_2d, NO_LOOP|NDF_INPLACE, 1, 1, ain, aout };

    sign = NUM2INT(vsign);
    if (sign != 1 && sign != -1) {
        rb_raise(rb_eArgError,"second argument (sign) must be 1 or -1");
    }
    GetNArray(vna,na);
    ndim = NA_NDIM(na);
    if (ndim<2) {
        rb_raise(nary_eDimensionError,"ndim(=%d) should >= 2",ndim);
    }

    shape[1] = NA_SHAPE(na)[ndim-1];

    shape[0] = NA_SHAPE(na)[ndim-2];

    vans = na_ndloop3(&ndf, &sign, 1, vna);
    RB_GC_GUARD(vna);
    return vans;
}

.dft_3d(narray, sign) ⇒ Numo::DComplex

3-dimentional Complex Discrete Fourier Transform along the last 3 dimensions.

Parameters:

  • narray (Numo::DComplex) —

    Input NArray with at least 3 dimensions.

  • sign (Numeric) —

    the sign of the exponent in the formula that defines the Fourier transform. It can be -1 (= FFTW_FORWARD) or +1 (= FFTW_BACKWARD).

Returns:

  • (Numo::DComplex) —

    Result DComplex NArray with shape = [.., nz, ny, nx].



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# File 'ext/numo/fftw/fftw.c', line 187

static VALUE
numo_fftw_dft_3d(VALUE mod, VALUE vna, VALUE vsign)
{
    narray_t *na;
    VALUE vans;
    int ndim;
    int sign=-1;
    size_t shape[3];
    ndfunc_arg_in_t ain[1] = {{cDC,3}};
    ndfunc_arg_out_t aout[1] = {{cDC,3,shape}};
    ndfunc_t ndf = { iter_fftw_dft_3d, NO_LOOP|NDF_INPLACE, 1, 1, ain, aout };

    sign = NUM2INT(vsign);
    if (sign != 1 && sign != -1) {
        rb_raise(rb_eArgError,"second argument (sign) must be 1 or -1");
    }
    GetNArray(vna,na);
    ndim = NA_NDIM(na);
    if (ndim<3) {
        rb_raise(nary_eDimensionError,"ndim(=%d) should >= 3",ndim);
    }

    shape[2] = NA_SHAPE(na)[ndim-1];

    shape[1] = NA_SHAPE(na)[ndim-2];

    shape[0] = NA_SHAPE(na)[ndim-3];

    vans = na_ndloop3(&ndf, &sign, 1, vna);
    RB_GC_GUARD(vna);
    return vans;
}