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Chris@19: You can install single and long-double precision versions of FFTW,
Chris@19: which replace double with float and long double,
Chris@19: respectively (see Installation and Customization). To use these
Chris@19: interfaces, you:
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-lfftw3f or
Chris@19: -lfftw3l instead of (or in addition to) -lfftw3. (You
Chris@19: can link to the different-precision libraries simultaneously.)
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Chris@19: <fftw3.h> header file.
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Chris@19: fftw_complex becomes fftwf_complex, fftw_execute
Chris@19: becomes fftwf_execute, etcetera.)
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Chris@19: double with float or long double for
Chris@19: subroutine parameters.
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Chris@19: Depending upon your compiler and/or hardware, long double may not
Chris@19: be any more precise than double (or may not be supported at all,
Chris@19: although it is standard in C99).
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We also support using the nonstandard __float128
Chris@19: quadruple-precision type provided by recent versions of gcc on
Chris@19: 32- and 64-bit x86 hardware (see Installation and Customization).
Chris@19: To use this type, link with -lfftw3q -lquadmath -lm (the
Chris@19: libquadmath library provided by gcc is needed for
Chris@19: quadruple-precision trigonometric functions) and use ‘fftwq_’
Chris@19: identifiers.
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