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Highlights from
SeisLab 3.01

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SeisLab 3.01

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24 Jul 2007 (Updated )

Release 10.0301 of a collection of functions for analysis/display of seismic and well-log data.

Seismic_examples2.m
% Seismic_examples2
%       Examples of the usage of seismic functions 

keep WF
presets
global S4M   %#ok


%     Create a minimum-phase wavelet
wavelet=s_create_wavelet({'type','min-phase'},{'step',1});

%     Create constant-Q filters for Q = 150,100,80,60 and 1 sec travel time
qfilters=s_create_qfilter({'q',[150,100,80,60]},{'times',1000},{'step',1});

%     Convolve the constant-Q filters with the wavelet
qwavelets=s_convolve(qfilters,wavelet);

%     Prepend the original wavelet (since the original wavelet is shorter 
%     than the filtered ones the missing samples are, by default, set to 
%     NaN's; this will give a warning in R 14, if the data set is plotted}
wavelets=s_append(wavelet,qwavelets);

%     Give the data set "wavelets" a descriptive name
wavelets.name='Original wavelet and its Q-filtered versions';

%     Plot the result with the following conditions:
%         plot only the first 200 ms;
%         annotate traces 2 to 5 with the Q-value of the filter (the Q-value
%             of the first trace is NaN as it is the original wavelet); 
%         fill the wiggle troughs with light gray
s_wplot(wavelets,{'times',0,200},{'aindex',2:5},{'annotation','Q'}, ...
       {'trough_fill',[0.7,0.7,0.7]});

%     Display real and imaginary parts of the Fourier transform of the wavelets
%     for frequencies from 0 to 80 Hz
ftwavelets=s_fft(wavelets,{'output','ft'});
s_compare(real(ftwavelets),imag(ftwavelets),{'times',0,80})
mytitle('Real (black) and imaginary (red) parts of the Fourier transform of the wavelets')

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