Talk:CSI Adelaide: Was Trayvon Martin murdered?

Hellp people..

I wrote a little bit of Matlab / GNU-octave code to generate spectrograms.

Question: Is there any space on the Wiki that I can use to upload source-code and atat et cetera...

Source code is as follows:

clear

%% An example of a Speech spectrogram, in GNU Octave

filename_01 = "trayvon_martin_gunshot.wav"

[x, Fs] = auload(file_in_loadpath(filename_01)); % load the audio file

% reduce to a single chanel, for now... x = mean(x,2);

% trace print the number of samples Sx = size(x) % trace print eh sampling frequency Fs

% set up some important parameters step = fix(2*Fs/1000);  % one spectral slice every 2 ms window = fix(20*Fs/1000);  % 20 ms data window fftn = 2^nextpow2(window);  % next highest power of 2

% take the spectrogram [S, f, t] = specgram(x, fftn, Fs, window, window-step);

% adjust the spectrogram data S = abs(S(2:fftn*4000/Fs,:));  % magnitude in range 0<f<=4000 Hz. S = S/max(S(:));  % normalize magnitude so that max is 0 dB. S = max(S, 10^(-40/10));  % clip below -40 dB. S = min(S, 10^(-3/10));  % clip above -3 dB.

% display the data imagesc(t, f, flipud(log(S)));  % display in log scale title("An example spectrogram"); xlabel("time (s)"); ylabel("freq. (Hz.)"); grid on

print -djpeg "trayvon_martin_gunshot.jpg"

Just a quick Math test.

\int_{-N}^{N} e^x\, dx \int_{-N}^{N} e^x\, dx