Function
NumCosmoMathSpectralcompute_d_row
Declaration [src]
void
ncm_spectral_compute_d_row (
gdouble* row_data,
glong offset,
gdouble coeff
)
Description [src]
Computes row k of the first derivative operator $\frac{d}{dx}$ that maps Chebyshev coefficients to Gegenbauer $C^{(2)}_k$ coefficients.
Input: Chebyshev $T_n(x)$ basis coefficients (columns) Output: $\langle C^{(2)}_k, f’ \rangle$ - projection of $f’$ (row k)
Mathematical formula: $$ \langle C^{(2)}k, f’ \rangle = c{k+1} - c_{k+3} $$ where $c_n$ are the input Chebyshev coefficients.
Adds to existing row data (for linear combinations of operators).
Matrix entries for row k: - column k+1: coeff * 1.0 - column k+3: coeff * (-1.0).