Add --stats-range

dump1090.c

@@ -702,6 +702,7 @@ void showHelp(void) {
 "--aggressive             More CPU for more messages (two bits fixes, ...)\n"
 "--mlat                   display raw messages in Beast ascii mode\n"
 "--stats                  With --ifile print stats at exit. No other output\n"
+"--stats-range            Collect/show range histogram\n"
 "--stats-every <seconds>  Show and reset stats every <seconds> seconds\n"
 "--onlyaddr               Show only ICAO addresses (testing purposes)\n"
 "--metric                 Use metric units (meters, km/h, ...)\n"
@@ -1032,6 +1033,8 @@ int main(int argc, char **argv) {
         } else if (!strcmp(argv[j],"--stats")) {
             if (!Modes.stats)
                 Modes.stats = (uint64_t)1 << 60; // "never"
+        } else if (!strcmp(argv[j],"--stats-range")) {
+            Modes.stats_range_histo = 1;
         } else if (!strcmp(argv[j],"--stats-every") && more) {
             Modes.stats = (uint64_t) (1000 * atof(argv[++j]));
         } else if (!strcmp(argv[j],"--snip") && more) {

dump1090.h

@@ -332,6 +332,7 @@ struct {                             // Internal state
     int   interactive_rows;          // Interactive mode: max number of rows
     uint64_t interactive_display_ttl;// Interactive mode: TTL display
     uint64_t stats;                  // Interval (millis) between stats dumps,
+    int   stats_range_histo;         // Collect/show a range histogram?
     int   onlyaddr;                  // Print only ICAO addresses
     int   metric;                    // Use metric units
     int   mlat;                      // Use Beast ascii format for raw data output, i.e. @...; iso *...;

stats.c

@@ -57,6 +57,8 @@ void add_timespecs(const struct timespec *x, const struct timespec *y, struct ti
     z->tv_nsec = z->tv_nsec % 1000000000L;
 }
 
+static void display_range_histogram(struct stats *st);
+
 void display_stats(struct stats *st) {
     int j;
     time_t tt_start, tt_end;
@@ -172,10 +174,79 @@ void display_stats(struct stats *st) {
                (unsigned long long) background_cpu_millis);
     }
 
+    if (Modes.stats_range_histo)
+        display_range_histogram(st);
 
     fflush(stdout);
 }
 
+static void display_range_histogram(struct stats *st)
+{
+    uint32_t peak;
+    int i, j;
+    int heights[RANGE_BUCKET_COUNT];
+
+#if 0
+#define NPIXELS 4
+    char *pixels[NPIXELS] = { ".", "o", "O", "|" };
+#else
+    // UTF-8 bar symbols
+#define NPIXELS 8
+    char *pixels[NPIXELS] = {
+        "\xE2\x96\x81",
+        "\xE2\x96\x82",
+        "\xE2\x96\x83",
+        "\xE2\x96\x84",
+        "\xE2\x96\x85",
+        "\xE2\x96\x86",
+        "\xE2\x96\x87",
+        "\xE2\x96\x88"
+    };
+#endif
+
+    printf ("Range histogram:\n\n");
+
+    for (i = 0, peak = 0; i < RANGE_BUCKET_COUNT; ++i) {
+        if (st->range_histogram[i] > peak)
+            peak = st->range_histogram[i];
+    }
+
+    for (i = 0; i < RANGE_BUCKET_COUNT; ++i) {
+        heights[i] = st->range_histogram[i] * 20.0 * NPIXELS / peak;
+        if (st->range_histogram[i] > 0 && heights[i] == 0)
+            heights[i] = 1;
+    }
+
+    for (j = 0; j < 20; ++j) {
+        for (i = 0; i < RANGE_BUCKET_COUNT; ++i) {
+            int pheight = heights[i] - ((19 - j) * NPIXELS);
+            if (pheight <= 0)
+                printf(" ");
+            else if (pheight >= NPIXELS)
+                printf("%s", pixels[NPIXELS-1]);
+            else
+                printf("%s", pixels[pheight]);
+        }
+        printf("\n");
+    }
+
+    for (i = 0; i < RANGE_BUCKET_COUNT/4; ++i) {
+        printf("----");
+    }
+    printf("\n");
+
+    for (i = 0; i < RANGE_BUCKET_COUNT/4; ++i) {
+        printf(" '  ");
+    }
+    printf("\n");
+
+    for (i = 0; i < RANGE_BUCKET_COUNT/4; ++i) {
+        int midpoint = round((i*4+1.5) * Modes.maxRange / RANGE_BUCKET_COUNT / 1000);
+        printf("%03d ", midpoint);
+    }
+    printf("km\n");
+}
+
 void reset_stats(struct stats *st) {
     static struct stats st_zero;
     *st = st_zero;
@@ -259,5 +330,8 @@ void add_stats(const struct stats *st1, const struct stats *st2, struct stats *t
     // aircraft
     target->unique_aircraft = st1->unique_aircraft + st2->unique_aircraft;
     target->single_message_aircraft = st1->single_message_aircraft + st2->single_message_aircraft;
-}
 
+    // range histogram
+    for (i = 0; i < RANGE_BUCKET_COUNT; ++i)
+        target->range_histogram[i] = st1->range_histogram[i] + st2->range_histogram[i];
+}

stats.h

@@ -119,6 +119,10 @@ struct stats {
     unsigned int unique_aircraft;
     // we saw only a single message
     unsigned int single_message_aircraft;
+
+    // range histogram
+#define RANGE_BUCKET_COUNT 76
+    uint32_t range_histogram[RANGE_BUCKET_COUNT];
 };    
 
 void add_stats(const struct stats *st1, const struct stats *st2, struct stats *target);

track.c

@@ -128,6 +128,21 @@ static double greatcircle(double lat0, double lon0, double lat1, double lon1)
     return 6371e3 * acos(sin(lat0) * sin(lat1) + cos(lat0) * cos(lat1) * cos(fabs(lon0 - lon1)));
 }
 
+static void update_range_histogram(double lat, double lon)
+{
+    if (Modes.stats_range_histo && (Modes.bUserFlags & MODES_USER_LATLON_VALID)) {
+        double range = greatcircle(Modes.fUserLat, Modes.fUserLon, lat, lon);
+        int bucket = round(range / Modes.maxRange * RANGE_BUCKET_COUNT);
+
+        if (bucket < 0)
+            bucket = 0;
+        else if (bucket >= RANGE_BUCKET_COUNT)
+            bucket = RANGE_BUCKET_COUNT-1;
+
+        ++Modes.stats_current.range_histogram[bucket];
+    }
+}
+
 // return true if it's OK for the aircraft to have travelled from its last known position
 // to a new position at (lat,lon,surface) at a time of now.
 static int speed_check(struct aircraft *a, struct modesMessage *mm, double lat, double lon, uint64_t now, int surface)
@@ -416,6 +431,7 @@ static void updatePosition(struct aircraft *a, struct modesMessage *mm, uint64_t
         a->pos_nuc = new_nuc;
         a->seenLatLon      = a->seen;
 
+        update_range_histogram(new_lat, new_lon);
     }
 }