Trapezoidal window function

Figure 1.36 Various selected apodization window functions (a) an unweighted FID (b) linear apodization (c) increasing exponential multiplication (d) trapezoidal multiplication (e) decreasing exponential multiplication (f) convolution differ-...

Explore the effect of other window functions, such as the triangular function (see exercise 7.5-1 under instruction 24), a trapezoidal function, a Gaussian, a Lorentzian, or whatever. 

Fourier transformation of a FID, which has not decayed to zero intensity causes a distortion ("wiggles") at the base of peaks in the spectrum. By applying a suitable window function WDW the FID will decay smoothly to zero. A variety of window functions options are available, none, exponential EM, gaussian GM, sine SINE, squared sine QSINE and trapezoidal TRAP function. The best type of window function depends on the appearance of the FID and the resulting spectrum. Consequently where possible it is best to fit the window function interactively. 

If we are interested in the energy and angular distributions of the ejected electrons, we choose a pulse which ramps back down to zero over a few additional cycles (a trapezoidal pulse) and then perform an analysis of the final wave function [15]. We define a window operator... 

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