Computes the backward Trigonometric Transform of type specified by the parameter.
- doubleford_backward_trig_transform,floatfors_backward_trig_transform,array of sizenfor staggered2 transforms and of sizen+1 for all other transforms, wherenis the size of the problem. On input, contains data vector to be transformed. Note that the following values should be 0.0 up to rounding errors:
Otherwise, the routine will produce a warning, and the result of the computations for sine transforms may be wrong. The above restrictions meet the requirements of thePoisson Solver, which the TT interface is primarily designed for (for details, seeFast Poisson Solver Routines).Intel® MKL
- f andf[n] for sine transforms
- f[n] for staggered cosine transforms
- f for staggered sine transforms.
- MKL_INTarray of size 128. Contains integer data needed for Trigonometric Transform computations.
- doublearray of size 5n/2+2. Contains double-precision data needed for Trigonometric Transform computations.
- floatarray of size 5n/2+2. Contains single-precision data needed for Trigonometric Transform computations.
- Contains the transformed vector on output.
- Contains integer data needed for Trigonometric Transform computations. On output,iparis updated with thestatvalue.
- MKL_INT*. Contains the routine completion status, which is also written toipar.
The routine computes the backward Trigonometric Transform of type defined in the
?_init_trig_transformroutine and passed to
ipararray. The size of the problem
n, which determines sizes of the array parameters, is also passed to the routine with the
ipararray and defined in the previously called
?_init_trig_transformroutine. The other data that facilitates the computation is created by
?_commit_trig_transformand supplied in
spar. For a detailed description of arrays
spar, refer to Common Parameters. The routine has a commit step, which calls the
?_commit_trig_transformroutine. The transform is computed according to formulas given in Transforms Implemented. The routine replaces the input vector
fwith the transformed vector.
If you need a copy of the data vector
fto be transformed, make the copy before calling the
- stat= 0
- The routine completed the task normally.
- stat= -100
- The routine stopped for any of the following reasons:
- An error in the user's data was encountered.
- Data inipar,dparorsparparameters became incorrect and/or inconsistent as a result of modifications.
- stat= -1000
- The routine stopped because of an FFT interface error.
- stat= -10000
- The routine stopped because its commit step failed to complete or the parameteriparwas altered by mistake.