added matlab

matlab/lfo/eval_lfo.asv

@@ -0,0 +1,34 @@
+function eval_lfo()
+
+L = 10000;
+fs = 44100;
+fstart = 40;
+fend = 400;
+df = (fend-fstart)/L;
+
+ip = 0 % phase of the first output sample in radians
+w = freq*pi / samplerate
+b1 = 2.0 * cos(w)
+
+% Init
+y1=sin(ip-w)
+y2=sin(ip-2*w)
+
+% Loop
+for n=1:L,
+    
+y0 = b1*y1 - y2
+y2 = y1
+y1 = y0
+
+
+close all
+
+figure;
+plot(1:L, vsaw, 1:L, vblit); grid;
+
+wavwrite(0.5*vtri, fs, 'tri.wav');
+wavwrite(0.5*vsqr, fs, 'sqr.wav');
+wavwrite(0.5*vsaw, fs, 'saw.wav');
+wavwrite(0.5*vblit, fs, 'blit.wav');
+

matlab/lfo/eval_lfo.m

@@ -0,0 +1,44 @@
+function eval_lfo()
+
+L = 10000;
+fs = 44100;
+fstart = 44;
+fend = 400;
+df = (fend-fstart)/L;
+
+ip = 0 % phase of the first output sample in radians
+
+% Init
+
+% Loop
+f = fstart;
+fchg = 1;
+
+y1=sin(ip-f*pi / fs);
+y2=sin(ip-2*f*pi / fs);
+
+for n=1:L,
+
+if fchg == 1,
+    b1 = 2.0 * cos(f*pi / fs);
+    fchg = 1000;
+end;
+
+y0 = b1*y1 - y2;
+y2 = y1;
+y1 = y0;
+
+fchg = fchg - 1;
+
+lfo(n) = y0;
+f = f + df;
+
+close all
+
+end;
+
+figure;
+plot(1:L, lfo); grid;
+
+wavwrite(0.5*lfo, fs, 'lfo.wav');
+

matlab/lfo/eval_lfo2.asv

@@ -0,0 +1,47 @@
+function eval_lfo2()
+
+L = 80000;
+fs = 48000;
+fstart = 10;
+fend = 1000;
+df = (fend-fstart)/L;
+
+ip = 0.0 % phase of the first output sample in radians
+
+% Init
+
+% Loop
+f = fstart;
+fchg = 0;
+
+ylast = 0;
+a = 0.5;
+b = 2.0 * sin(f*pi / fs);
+y0 = a*cos(2*pi*ip);
+y1 = a*sin(2*pi*ip);
+
+for n=1:L,
+
+y0 = y0 - b*y1;
+y1 = y1 + b*y0;
+
+fchg = (mod(n, 1000) == 0);
+
+if fchg
+    b = 2.0 * sin(f*pi / fs);
+end
+
+ylast = y1;
+
+lfo(n) = y0;
+f = f + df;
+
+close all
+
+end;
+
+figure;
+plot(1:L, lfo); grid;
+
+wavwrite(0.5*lfo, fs, 'lfo.wav');
+

matlab/lfo/eval_lfo2.m

@@ -0,0 +1,47 @@
+function eval_lfo2()
+
+L = 80000;
+fs = 48000;
+fstart = 10;
+fend = 5000;
+df = (fend-fstart)/L;
+
+ip = 0.0 % phase of the first output sample in radians
+
+% Init
+
+% Loop
+f = fstart;
+fchg = 0;
+
+ylast = 0;
+a = 0.5;
+b = 2.0 * sin(f*pi / fs);
+y0 = a*cos(2*pi*ip);
+y1 = a*sin(2*pi*ip);
+
+for n=1:L,
+
+y0 = y0 - b*y1;
+y1 = y1 + b*y0;
+
+fchg = (mod(n, 1000) == 0);
+
+if fchg
+    b = 2.0 * sin(f*pi / fs);
+end
+
+ylast = y1;
+
+lfo(n) = y0;
+f = f + df;
+
+close all
+
+end;
+
+figure;
+plot(1:L, lfo); grid;
+
+wavwrite(0.5*lfo, fs, 'lfo.wav');
+

matlab/lfo/eval_smooth.asv

@@ -0,0 +1,21 @@
+function eval_smooth(Ta)
+
+fs = 10000;
+
+b = 1;
+if (abs(Ta) > 0)
+    b = 1/(abs(Ta)*fs);
+end;
+
+a = 1 - b;
+
+x = [ zeros(1, 1000) ones(1, 1000) zeros(1, 1000)];
+
+y = 0;
+for i=1:length(x)
+    if (Ta < 0)
+    y = b*x(i) + a*y;
+    yn(i) = y;
+end;
+
+plot(yn); grid;

matlab/lfo/eval_smooth.m

@@ -0,0 +1,34 @@
+function eval_smooth(Ta)
+
+fs = 10000;
+
+b = 1;
+if (abs(Ta) > 0)
+    b = 1/(abs(Ta)*fs);
+end;
+
+a = 1 - b;
+
+x = [ zeros(1, 1000) ones(1, 1000) zeros(1, 1000)];
+N = length(x);
+
+y = 0;
+y1 = 0;
+for i=1:length(x)
+    y1 = b*x(i) + a*y1;
+%    if (Ta > 0)
+        y1n(i) = y1;
+%    else
+        y2n(i) = 2*x(i) - y1;
+%    end
+end;
+
+subplot(3, 1, 1)
+plot(1:N, x, 'r'); grid;
+xlabel('Original LFO Wellenform (Square)')
+subplot(3, 1, 2)
+plot(1:N, y1n, 'r'); grid;
+xlabel('Positive smoothed')
+subplot(3, 1, 3)
+plot(1:N, y2n, 'r'); grid;
+xlabel('Negative smoothed')