SHFS8R - Shift a uniformly-sampled real-valued function y(x) via
a table of 8-coefficient sinc approximations.
shfs8r shift a uniformly-sampled real function via a table of 8-coeff. sinc
approximations.
Function Prototypes:
void shfs8r (float dx, int nxin, float fxin, float yin[],
float yinl, float yinr, int nxout, float fxout, float yout[]);
Input:
dx x sampling interval for both input and output y(x)
nxin number of x values at which y(x) is input
fxin x value of first sample input
yin array[nxin] of input y(x) values: yin[0] = y(fxin), etc.
yinl value used to extrapolate yin values to left of yin[0]
yinr value used to extrapolate yin values to right of yin[nxin-1]
nxout number of x values a which y(x) is output
fxout x value of first sample output
Output:
yout array[nxout] of output y(x) values: yout[0] = y(fxout), etc.
Notes:
Because extrapolation of the input function y(x) is defined by the
left and right values yinl and yinr, the output samples defined by
dx, nxout, and fxout are not restricted to lie within the range of
input sample locations defined by dx, nxin, and fxin.
The maximum error for frequencies less than 0.6*nyquist is less
than one percent.
Author: Dave Hale, Colorado School of Mines, 06/02/89