comparison saitools/removepeaks.c @ 0:5242703e91d3 tip

Initial checkin for AIM92 aimR8.2 (last updated May 1997).

+/*
+    Copyright (c) Applied Psychology Unit, Medical Research Council. 1993
+    ===========================================================================
+
+    Permission to use, copy, modify, and distribute this software without fee 
+    is hereby granted for research purposes, provided that this copyright 
+    notice appears in all copies and in all supporting documentation, and that 
+    the software is not redistributed for any fee (except for a nominal 
+    shipping charge). Anyone wanting to incorporate all or part of this 
+    software in a commercial product must obtain a license from the Medical 
+    Research Council.
+
+    The MRC makes no representations about the suitability of this 
+    software for any purpose.  It is provided "as is" without express or 
+    implied warranty.
+ 
+    THE MRC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
+    ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL 
+    THE A.P.U. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES 
+    OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 
+    WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 
+    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 
+    SOFTWARE.
+*/
+
+/*-------------------------------------------------------------------------*/
+
+/*  removepeaks.c
+*  ---------------
+*
+* M.Akeroyd. Summer 1993. Revised Winter 1994.
+*/
+
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "tip.h"
+
+
+
+
+extern struct Peak peak[MAX_PEAKS];    /* all channels */
+extern struct NextEvent nextevent[MAX_PEAKS];
+
+extern double removevalue;
+extern inputdata[MAX_DATA];
+
+
+
+
+/*-------------------------------------------------------------------------*/
+
+
+
+int removepeaks(int total_peaks)
+{
+  /* What this code does:
+   * 
+   * Its purpose is to remove, completely, any peak that is very small, 
+   * and perhaps shouldn't be regarded as being there. This is because they 
+   * tend to clutter up tents and glaciers.
+   *
+   * So, go through each peak. If F(n) < (F[n-1]*removevalue)  AND 
+   * F(n) < (F[n+1]*removevalue), then remove it. Exactly what samples are 
+   * removed depends on the next events.
+   *
+   * At the end, call findpeaksreverse again, to reset the nextevent counters.
+   * RETURN the new value of total_peaks.
+   *
+   */
+
+  int n;
+  int sample;
+
+/*--------------------------------------*/
+
+  for (n=2; n<total_peaks; n++)
+    
+    if ((peak[n].mag < (int) (peak[n-1].mag * removevalue)) &&
+	(peak[n].mag < (int) (peak[n+1].mag * removevalue))) {
+      /* remove peak */
+      for (sample = peak[n].sample; sample <= nextevent[n-1].sample; sample++)
+	inputdata[sample] = 0;
+      for (sample = peak[n].sample; sample >= nextevent[n].sample; sample--)
+	inputdata[sample] = 0;
+    }
+
+/*--------------------------------------*/
+
+  /* repeat for first and last peaks */
+
+  if (peak[1].mag  < (int) (peak[2].mag * removevalue)) {
+    for (sample = peak[1].sample; sample >= nextevent[1].sample; sample--)
+      inputdata[sample] = 0;
+  }
+
+  n=total_peaks;
+
+  if (peak[n].mag < (int) (peak[n-1].mag * removevalue)) {
+     for (sample = peak[n].sample; sample <= nextevent[n-1].sample; sample++)
+      inputdata[sample] = 0;
+  }
+    
+/*--------------------------------------*/
+  
+  findpeaksreverse();
+  return total_peaks;
+
+}
+      
+
+
+
+/* The End */
+/*-------------------------------------------------------------------------*/