diff options
Diffstat (limited to 'src/average.c')
| -rw-r--r-- | src/average.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/average.c b/src/average.c new file mode 100644 index 0000000..2c46ce3 --- /dev/null +++ b/src/average.c @@ -0,0 +1,192 @@ +/* -------------------------- average ----------------------------------------- */
+/* */
+/* Calculates the average value of the last N elements. */
+/* Written by Olaf Matthes (olaf.matthes@gmx.de) */
+/* Get source at http://www.akustische-kunst.org/puredata/maxlib/ */
+/* */
+/* This program is free software; you can redistribute it and/or */
+/* modify it under the terms of the GNU General Public License */
+/* as published by the Free Software Foundation; either version 2 */
+/* of the License, or (at your option) any later version. */
+/* */
+/* This program is distributed in the hope that it will be useful, */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
+/* GNU General Public License for more details. */
+/* */
+/* You should have received a copy of the GNU General Public License */
+/* along with this program; if not, write to the Free Software */
+/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+/* */
+/* Based on PureData by Miller Puckette and others. */
+/* */
+/* ---------------------------------------------------------------------------- */
+
+#include "m_pd.h"
+#include <math.h>
+
+#define MAX_ARG 128 /* maximum number of items to average */
+
+static char *version = "average v0.1, written by Olaf Matthes <olaf.matthes@gmx.de>";
+
+typedef struct average
+{
+ t_object x_ob;
+ t_clock *x_clock;
+ t_inlet *x_inindex;
+ t_outlet *x_outfloat; /* output the average */
+ t_outlet *x_outtendency; /* outputs the tendency of the average */
+ t_int x_limit; /* indicates if input is 'blocked' (1) */
+ t_int x_index; /* the number of elements to average */
+ t_float x_input[MAX_ARG]; /* stores the input values we need for averaging */
+ t_int x_inpointer; /* actual position in above array */
+ t_float x_average; /* what do you guess ? */
+ t_float x_lastaverage;
+ t_int x_mode; /* how to average: linear or geometric */
+
+} t_average;
+
+ /* there must be a function for this in math.h but how is the
+ german 'Fakultät' called in english ???? */
+static int normalise(int i)
+{
+ int ret = i;
+ while(i--)
+ {
+ if(i == 0)break;
+ ret += i;
+ }
+ return (ret);
+}
+
+static void average_float(t_average *x, t_floatarg f)
+{
+ int i, j = 0;
+ t_float tendency;
+ t_float geo = 1.0;
+
+ x->x_average = 0;
+ /* put value into array */
+ x->x_input[x->x_inpointer] = f;
+ /* calulate average */
+ for(i = 0; i < x->x_index; i++)
+ {
+ if(x->x_mode == 0) /* linear */
+ {
+ x->x_average += x->x_input[i] * (1.0 / (float)x->x_index);
+ }
+ else if(x->x_mode == 1) /* geometric */
+ {
+ if(x->x_input[i] == 0)x->x_input[i] = 0.001; /* need to cheat a bit... */
+ geo *= x->x_input[i];
+ if(i == x->x_index - 1)
+ x->x_average = pow(geo, (1.0/(float)x->x_index));
+ }
+ else if(x->x_mode == 2) /* weighted */
+ {
+ x->x_average += x->x_input[(j + x->x_inpointer + x->x_index) % x->x_index] * (float)(x->x_index - (i + 1));
+ j--; /* go back in array */
+ /* normalise output */
+ if(i == x->x_index - 1)
+ x->x_average = x->x_average / (float)normalise(x->x_index - 1);
+ } else post("average: internal error!");
+ }
+ if(++x->x_inpointer > x->x_index)
+ {
+ x->x_inpointer = 0;
+ if(x->x_lastaverage < x->x_average)
+ {
+ tendency = 1; /* getting more */
+ }
+ else if(x->x_lastaverage > x->x_average)
+ {
+ tendency = -1; /* getting less */
+ }
+ else tendency = 0; /* nothing has changed */
+ outlet_float(x->x_outtendency, tendency);
+ x->x_lastaverage = x->x_average;
+ }
+ outlet_float(x->x_outfloat, x->x_average);
+}
+
+static void average_index(t_average *x, t_floatarg f)
+{
+ x->x_index = (t_int)f;
+ if(x->x_index > MAX_ARG)x->x_index = MAX_ARG;
+}
+
+static void average_reset(t_average *x)
+{
+ int i;
+ /* zeroe out the array */
+ for(i = 0; i < MAX_ARG; i++)x->x_input[i] = 0.0;
+ x->x_inpointer = 0;
+ x->x_average = 0;
+ x->x_lastaverage = 0;
+ post("average: reset");
+}
+
+static void average_linear(t_average *x)
+{
+ x->x_mode = 0;
+ post("average: linear");
+}
+
+static void average_geometric(t_average *x)
+{
+ x->x_mode = 1;
+ post("average: geometric");
+}
+
+static void average_weight(t_average *x)
+{
+ x->x_mode = 2;
+ post("average: weighted");
+}
+
+static void average_free(t_average *x)
+{
+ /* nothing to do */
+}
+
+static t_class *average_class;
+
+static void *average_new(t_floatarg f)
+{
+ int i;
+
+ t_average *x = (t_average *)pd_new(average_class);
+ x->x_inindex = inlet_new(&x->x_ob, &x->x_ob.ob_pd, gensym("float"), gensym("index"));
+ x->x_outfloat = outlet_new(&x->x_ob, gensym("float"));
+ x->x_outtendency = outlet_new(&x->x_ob, gensym("float"));
+
+ /* zeroe out the array */
+ for(i = 0; i < MAX_ARG; i++)x->x_input[i] = 0.0;
+ x->x_index = (t_int)f;
+ if(x->x_index > MAX_ARG)
+ {
+ x->x_index = MAX_ARG;
+ post("average: set number of items to %d", x->x_index);
+ }
+ x->x_inpointer = 0;
+ x->x_average = 0;
+ x->x_mode = 0;
+#ifndef MAXLIB
+ post(version);
+#endif
+ return (void *)x;
+}
+
+void average_setup(void)
+{
+ average_class = class_new(gensym("average"), (t_newmethod)average_new,
+ (t_method)average_free, sizeof(t_average), 0, A_DEFFLOAT, 0);
+ class_addmethod(average_class, (t_method)average_reset, gensym("reset"), 0);
+ class_addmethod(average_class, (t_method)average_linear, gensym("linear"), 0);
+ class_addmethod(average_class, (t_method)average_geometric, gensym("geometric"), 0);
+ class_addmethod(average_class, (t_method)average_weight, gensym("weight"), 0);
+ class_addfloat(average_class, average_float);
+ class_addmethod(average_class, (t_method)average_index, gensym("index"), A_FLOAT, 0);
+ class_sethelpsymbol(average_class, gensym("maxlib/help-average.pd"));
+}
+
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