5.3 Discrete Sine Transform

dst( X[, type=1])
Replaces the columns of a dense real matrix with their discrete sine transforms. The second argument, an integer between 1 and 4, denotes the type of transform (DST-I, DST-II, DST-III, DST-IV). These transforms are defined as follows (for a matrix with n rows).

\begin{eqnarray*}
\mbox{DST-I:} \qquad
X[k,:] & := &
2 \sum_{j=0}^{n-1} X[j,:...
...n-1} X[j,:] \sin(\pi (j+1/2)(k+1/2)/n),
\qquad k=0,\ldots,n-1.
\end{eqnarray*}


idst( X[, type=1])
Replaces the columns of a dense real matrix with the inverses of the discrete sine transforms defined above.