wavesynth: basic sample computation

artiq/wavesynth/compute_samples.py

@@ -0,0 +1,69 @@
+from copy import copy
+from math import cos, pi
+
+import cairoplot
+
+
+class Spline:
+    def __init__(self, c):
+        self.set_coefficients(c)
+
+    def set_coefficients(self, c):
+        self.c = copy(c)
+
+    def next(self):
+        r = self.c[0]
+        for i in range(len(self.c)-1):
+            self.c[i] += self.c[i+1]
+        return r
+
+
+class SplinePhase:
+    def __init__(self, c):
+        self.c = [0.0]
+        self.set_coefficients(c)
+
+    def clear(self):
+        self.c[0] = 0.0
+
+    def set_coefficients(self, c):
+        self.c = self.c[0:1] + c[1:]
+        self.c0 = self.c[0]
+
+    def next(self):
+        r = self.c[0] + self.c0
+        for i in range(len(self.c)-1):
+            self.c[i] += self.c[i+1] % 1.0
+        return r
+
+
+class DDS:
+    def __init__(self, c_amplitude, c_phase):
+        self.amplitude = Spline(c_amplitude)
+        self.phase = SplinePhase(c_phase)
+
+    def next(self):
+        return self.amplitude.next()*cos(2*pi*self.phase.next())
+
+
+class Wave:
+    def __init__(self, c_bias, c_dds_amplitude, c_dds_phase):
+        self.bias = Spline(c_bias)
+        self.dds = DDS(c_dds_amplitude, c_dds_phase)
+
+    def next(self):
+        return self.bias.next() + self.dds.next()
+
+
+if __name__ == "__main__":
+    w = Wave([0.0, 0.0, 0.0], [0.0, 0.0, 0.01], [0.0, 0.0, 0.0005])
+    x = list(range(400))
+    y = [w.next() for i in range(100)]
+    w.dds.amplitude.c[2] = -0.01
+    y += [w.next() for i in range(100)]
+    w.dds.amplitude.c[2] = -0.01
+    w.dds.phase.c[2] = -0.0005
+    y += [w.next() for i in range(100)]
+    w.dds.amplitude.c[2] = 0.01
+    y += [w.next() for i in range(100)]
+    cairoplot.scatter_plot("plot.png", [x, y])