1 files changed, 0 insertions, 226 deletions
diff --git a/include/filters.h b/include/filters.h
deleted file mode 100644
index e0d1c49..0000000
--- a/include/filters.h
+++ /dev/null
@@ -1,226 +0,0 @@
-/* this file contains a 37th attempt to write a general purpose iir filter toolset */
-
-/* defined as inline functions with call by reference to enable compiler ref/deref optim */
-
-/* the typedef */
-#ifndef T
-#define T float
-#endif
-
-
-/* the prototype for a word */
-#define P static inline void
-#define PP static void
-
-
-/* the 'reference' arguments */
-#define A *a
-#define B *b
-#define C *c
-#define D *d
-#define X *x
-#define Y *y
-#define S *s
-
-
-/* the opcodes */
-
-/* add */
-P cadd  (T X, T Y, T A, T B, T C, T D) { X = A + C; Y = B + D;}
-P cadd2 (T A, T B, T C, T D)           { A += C; B += D;}
-P vcadd  (T X, T A, T C)                { cadd(x,x+1,a,a+1,c,c+1); }
-P vcadd2 (T A, T C)                     { cadd2(a,a+1,c,c+1); }
-
-
-/* mul */
-P cmul_r (T X, T A, T B, T C, T D)    { X = A * C - B * D;}
-P cmul_i (T Y, T A, T B, T C, T D)    { Y = A * D + B * C;}
-P cmul (T X, T Y, T A, T B, T C, T D) 
-{
-    cmul_r (x, a, b, c, d);
-    cmul_i (y, a, b, c, d);
-}
-P cmul2 (T A, T B, T C, T D)
-{
-    T x = A;
-    T y = B;
-    cmul (&x, &y, a, b, c, d);
-    A = x;
-    B = y;
-}
-
-P vcmul  (T X, T A, T C)  { cmul(x,x+1,a,a+1,c,c+1); }
-P vcmul2 (T A, T C)       { cmul2(a,a+1,c,c+1); }
-
-
-/* norm */
-static inline float vcnorm(T X) { return hypot(x[0], x[1]); }
-
-
-
-/* swap */
-P vcswap(T Y, T X)
-{
-    float t[2] = {x[0], x[1]};
-    x[0] = y[0];
-    x[1] = y[1];
-    y[0] = t[0];
-    y[1] = t[1];
-}
-
-
-/* inverse */
-P vcinv(T Y, T X)
-{
-    float scale = 1.0f / vcnorm(x);
-    y[0] = scale * x[0];
-    y[1] = scale * x[1];
-}
-
-P vcinv1(T X)
-{
-    float scale = 1.0f / vcnorm(x);
-    x[0] *= scale;
-    x[1] *= scale;
-}
-
-/* exp */
-
-/* X = exp(Y) */
-P vcexp2 (T Y, T X)
-{
-    T r = exp(x[0]);
-    y[0] = cos (x[1]);
-    y[1] = sin (x[1]);
-    y[0] *= r;
-    y[1] *= r;
-}
-
-P vcexp1 (T X)
-{
-    T y[2];
-    vcexp2(y,x);
-    x[0] = y[0];
-    x[1] = y[1];
-}
-
-/* 
-   FILTERS
-
-   the transfer function is defined in terms of the "engineering" 
-   bilateral z-transform of the discrete impulse response h[n].
-
-   H(z) = Sum{n = -inf -> inf} h[n] z^(-n)
-
-   a unit delay operating on a singnal S(z) is therefore 
-   represented as z^(-1) S(z)
-
-*/
-
-
-
-
-
-
-
-/* biquads */
-
-/* biquad, orthogonal (poles & zeros), real in, out, state, pole, output */
-P biq_orth_r (T X, T Y, T S, T A, T C)
-{
-    Y = X + c[0] * s[0] - c[1] * s[1]; /* mind sign of c[1] */
-    vcmul2(s, a);
-    S += X;
-}
-
-
-/* biquad, orthogonal, complex one-pole, with scaling */
-
-/* complex one pole: (output = s[0] + is[1]): C / (1-A z^(-1))  */
-
-P one_pole_complex (T X, T Y, T S, T A, T C)
-{
-    vcmul(y, s, a);
-    vcadd2(y, x);
-    s[0] = y[0];
-    s[1] = y[1];
-    vcmul(y, s, c);
-}
-
-/* complex conj two pole:  (output = s[0]  : (Re(C) - Re(C*Conj(A))) / (1 - A z^(-1)) (1 - Conj(A) z^(-1)) */
-
-P two_pole_complex_conj (T X, T Y, T S, T A, T C)
-{
-    vcmul2(s, a);
-    s[0] += x[0];
-    y[0] = s[0] * c[0] - s[1] * c[1];
-}
-
-
-
-/* support functions for IIR filter design */
-
-/* evaluate pole and allzero TF in z^-1 given the complex zeros/poles:
-   p(z) (or p(z)^-1) = \product (1-z_i z^-1) */
-PP eval_zero_poly(float *val, float *arg, float *zeros, int nb_zeros)
-{
-    int i;
-    float a[2] = {arg[0], arg[1]};
-    vcinv1(a);
-    val[0] = 1.0f;
-    val[1] = 0.0f;
-    a[0] *= -1;
-    a[1] *= -1;
-    for (i=0; i<nb_zeros; i++){
-	float t[2];
-	vcmul(t, a, zeros + 2*i);
-	t[0] += 1.0f;
-	vcmul2(val, t);
-    }
-}
-
-PP eval_pole_poly(float *val, float *arg, float *poles, int nb_poles)
-{
-    eval_zero_poly(val, arg, poles, nb_poles);
-    vcinv1(val);
-}
-
-
-/* since it's more efficient to store half of the poles for a real impulse
-   response, these functions compute p(z) conj(p(conj(z)))  */
-
-PP eval_conj_zero_poly(float *val, float *arg, float *zeros, int nb_zeros)
-{
-    float t[2];
-    float a[2] = {arg[0], arg[1]};
-    eval_zero_poly(t, a, zeros, nb_zeros);
-    a[1] *= -1;
-    eval_zero_poly(val, a, zeros, nb_zeros);
-    val[1] *= -1;
-    vcmul2(val, t);
-}
-
-PP eval_conj_pole_poly(float *val, float *arg, float *poles, int nb_poles)
-{
-    eval_conj_zero_poly(val, arg, poles, nb_poles);
-    vcinv1(val);
-}
-
-PP eval_conj_pole_zero_ratfunc(float *val, float *arg, float *poles, float *zeros, int nb_poles, int nb_zeros)
-{
-    float t[2];
-    eval_conj_zero_poly(t, arg, zeros, nb_zeros);
-    eval_conj_pole_poly(val, arg, poles, nb_zeros);
-    vcmul2(val, t);
-}
-
-
-
-/* bandlimited IIR impulse:
-
-   * design analog butterworth filter
-   * obtain the partial fraction expansion of the transfer function
-   * determine the state increment as a function of fractional delay of impulse location 
-   (sample the impulse response)
-
-*/