41 lines
1.3 KiB
Matlab
41 lines
1.3 KiB
Matlab
function x = generate_sawtooth(amplitude, frequency, phase, fs, duration, duty)
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% generate_sawtooth: returns a matrix of sampled sawtooth wave
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% CONTRIBUTORS:
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% Ben Zhang: Function author
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% DOCUMENTATION:
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% phase shift is in number of periods
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% fs is the sampling frequency: how many sample points per second
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% duration is time in seconds
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% duty is a number between 0 and 1
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%duty does not apply for sawtooth wave
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% initialize local variables from input arguments
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n = fs * duration; % number of samples (length of matrix)
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dt = 1 / fs; % sampling period: time between two sample points
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period = 1 / frequency; % period of the wave
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% initialize a one dimensional zero matrix to be populated
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x = zeros(1, n);
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% populate the matrix
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for i = 1:n
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t = i * dt; % time of the i'th sample
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st = mod(frequency * t - phase, 1); % Progression through cycle
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slope = 2 * amplitude / period; % the incline slope from start to amplitude
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mid = period / 2;
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%part before the straght vertical line
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if(st < mid)
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x(i) = slope * st; % amplitude from start to +amplitude
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%part after the straght vertical line
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else
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x(i) = slope * (st - 0.5) - amplitude; %amplitude from -amplitude to start
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end
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end
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