/**
* Make a speed/distance map
*/
gdouble *vik_track_make_speed_dist_map ( const VikTrack *tr, guint16 num_chunks )
{
gdouble *v, *s, *t;
time_t t1, t2;
gint i, pt_count, numpts, index;
GList *iter;
gdouble duration, total_length, chunk_length;
if ( ! tr->trackpoints )
return NULL;
t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
duration = t2 - t1;
if ( !t1 || !t2 || !duration )
return NULL;
if (duration < 0) {
g_warning("negative duration: unsorted trackpoint timestamps?");
return NULL;
}
total_length = vik_track_get_length_including_gaps ( tr );
chunk_length = total_length / num_chunks;
pt_count = vik_track_get_tp_count(tr);
if (chunk_length <= 0) {
return NULL;
}
v = g_malloc ( sizeof(gdouble) * num_chunks );
s = g_malloc ( sizeof(double) * pt_count );
t = g_malloc ( sizeof(double) * pt_count );
// No special handling of segments ATM...
iter = tr->trackpoints->next;
numpts = 0;
s[0] = 0;
t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp;
numpts++;
while (iter) {
s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
numpts++;
iter = iter->next;
}
// Iterate through a portion of the track to get an average speed for that part
// This will essentially interpolate between segments, which I think is right given the usage of 'get_length_including_gaps'
index = 0; /* index of the current trackpoint. */
for (i = 0; i < num_chunks; i++) {
// Similar to the make_speed_map, but instead of using a time chunk, use a distance chunk
if (s[0] + i*chunk_length >= s[index]) {
gdouble acc_t = 0, acc_s = 0;
while (s[0] + i*chunk_length >= s[index]) {
acc_s += (s[index+1]-s[index]);
acc_t += (t[index+1]-t[index]);
index++;
}
v[i] = acc_s/acc_t;
}
else if (i) {
v[i] = v[i-1];
}
else {
v[i] = 0;
}
}
g_free(s);
g_free(t);
return v;
}
/**
* Make a distance/time map, heavily based on the vik_track_make_speed_map method
*/
gdouble *vik_track_make_distance_map ( const VikTrack *tr, guint16 num_chunks )
{
gdouble *v, *s, *t;
gdouble duration, chunk_dur;
time_t t1, t2;
int i, pt_count, numpts, index;
GList *iter;
if ( ! tr->trackpoints )
return NULL;
t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
duration = t2 - t1;
if ( !t1 || !t2 || !duration )
return NULL;
if (duration < 0) {
g_warning("negative duration: unsorted trackpoint timestamps?");
return NULL;
}
pt_count = vik_track_get_tp_count(tr);
v = g_malloc ( sizeof(gdouble) * num_chunks );
chunk_dur = duration / num_chunks;
s = g_malloc(sizeof(double) * pt_count);
t = g_malloc(sizeof(double) * pt_count);
iter = tr->trackpoints->next;
numpts = 0;
s[0] = 0;
t[0] = VIK_TRACKPOINT(iter->prev->data)->timestamp;
numpts++;
while (iter) {
s[numpts] = s[numpts-1] + vik_coord_diff ( &(VIK_TRACKPOINT(iter->prev->data)->coord), &(VIK_TRACKPOINT(iter->data)->coord) );
t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
numpts++;
iter = iter->next;
}
/* In the following computation, we iterate through periods of time of duration chunk_dur.
* The first period begins at the beginning of the track. The last period ends at the end of the track.
*/
index = 0; /* index of the current trackpoint. */
for (i = 0; i < num_chunks; i++) {
/* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
* find the first trackpoint outside the current interval, averaging the distance between intermediate trackpoints.
*/
if (t[0] + i*chunk_dur >= t[index]) {
gdouble acc_s = 0; // No need for acc_t
while (t[0] + i*chunk_dur >= t[index]) {
acc_s += (s[index+1]-s[index]);
index++;
}
// The only bit that's really different from the speed map - just keep an accululative record distance
v[i] = i ? v[i-1]+acc_s : acc_s;
}
else if (i) {
v[i] = v[i-1];
}
else {
v[i] = 0;
}
}
g_free(s);
g_free(t);
return v;
}
/**
* This uses the 'time' based method to make the graph, (which is a simpler compared to the elevation/distance)
* This results in a slightly blocky graph when it does not have many trackpoints: <60
* NB Somehow the elevation/distance applies some kind of smoothing algorithm,
* but I don't think any one understands it any more (I certainly don't ATM)
*/
gdouble *vik_track_make_elevation_time_map ( const VikTrack *tr, guint16 num_chunks )
{
time_t t1, t2;
gdouble duration, chunk_dur;
GList *iter = tr->trackpoints;
if (!iter || !iter->next) /* zero- or one-point track */
return NULL;
/* test if there's anything worth calculating */
gboolean okay = FALSE;
while ( iter ) {
if ( VIK_TRACKPOINT(iter->data)->altitude != VIK_DEFAULT_ALTITUDE ) {
okay = TRUE;
break;
}
iter = iter->next;
}
if ( ! okay )
return NULL;
t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
duration = t2 - t1;
if ( !t1 || !t2 || !duration )
return NULL;
if (duration < 0) {
g_warning("negative duration: unsorted trackpoint timestamps?");
return NULL;
}
gint pt_count = vik_track_get_tp_count(tr);
// Reset iterator back to the beginning
iter = tr->trackpoints;
gdouble *pts = g_malloc ( sizeof(gdouble) * num_chunks ); // The return altitude values
gdouble *s = g_malloc(sizeof(double) * pt_count); // calculation altitudes
gdouble *t = g_malloc(sizeof(double) * pt_count); // calculation times
chunk_dur = duration / num_chunks;
s[0] = VIK_TRACKPOINT(iter->data)->altitude;
t[0] = VIK_TRACKPOINT(iter->data)->timestamp;
iter = tr->trackpoints->next;
gint numpts = 1;
while (iter) {
s[numpts] = VIK_TRACKPOINT(iter->data)->altitude;
t[numpts] = VIK_TRACKPOINT(iter->data)->timestamp;
numpts++;
iter = iter->next;
}
/* In the following computation, we iterate through periods of time of duration chunk_dur.
* The first period begins at the beginning of the track. The last period ends at the end of the track.
*/
gint index = 0; /* index of the current trackpoint. */
gint i;
for (i = 0; i < num_chunks; i++) {
/* we are now covering the interval from t[0] + i*chunk_dur to t[0] + (i+1)*chunk_dur.
* find the first trackpoint outside the current interval, averaging the heights between intermediate trackpoints.
*/
if (t[0] + i*chunk_dur >= t[index]) {
gdouble acc_s = s[index]; // initialise to first point
while (t[0] + i*chunk_dur >= t[index]) {
acc_s += (s[index+1]-s[index]);
index++;
}
pts[i] = acc_s;
}
else if (i) {
pts[i] = pts[i-1];
}
else {
pts[i] = 0;
}
}
g_free(s);
g_free(t);
return pts;
}
/**
* @val_analyse_track:
* @trk: The track to be analyse
*
* Function to collect statistics, using the internal track functions
*/
static void val_analyse_track ( VikTrack *trk )
{
//val_reset ( TS_TRACK );
gdouble min_alt;
gdouble max_alt;
gdouble up;
gdouble down;
gdouble length = 0.0;
gdouble length_gaps = 0.0;
gdouble max_speed = 0.0;
gulong trackpoints = 0;
guint segments = 0;
tracks_stats[TS_TRACKS].count++;
trackpoints = vik_track_get_tp_count (trk);
segments = vik_track_get_segment_count (trk);
length = vik_track_get_length (trk);
length_gaps = vik_track_get_length_including_gaps (trk);
max_speed = vik_track_get_max_speed (trk);
if ( !trk->is_route ) {
// Eddington number will be in the current Units distance preference
gdouble e_len;
switch (a_vik_get_units_distance ()) {
case VIK_UNITS_DISTANCE_MILES: e_len = VIK_METERS_TO_MILES(length); break;
case VIK_UNITS_DISTANCE_NAUTICAL_MILES: e_len = VIK_METERS_TO_NAUTICAL_MILES(length); break;
//VIK_UNITS_DISTANCE_KILOMETRES
default: e_len = length/1000.0; break;
}
gdouble *gd = g_malloc ( sizeof(gdouble) );
*gd = e_len;
tracks_stats[TS_TRACKS].e_list = g_list_prepend ( tracks_stats[TS_TRACKS].e_list, gd );
}
int ii;
for (ii = 0; ii < G_N_ELEMENTS(tracks_stats); ii++) {
tracks_stats[ii].trackpoints += trackpoints;
tracks_stats[ii].segments += segments;
tracks_stats[ii].length += length;
tracks_stats[ii].length_gaps += length_gaps;
if ( max_speed > tracks_stats[ii].max_speed )
tracks_stats[ii].max_speed = max_speed;
}
if ( vik_track_get_minmax_alt (trk, &min_alt, &max_alt) ) {
for (ii = 0; ii < G_N_ELEMENTS(tracks_stats); ii++) {
if ( min_alt < tracks_stats[ii].min_alt )
tracks_stats[ii].min_alt = min_alt;
if ( max_alt > tracks_stats[ii].max_alt )
tracks_stats[ii].max_alt = max_alt;
}
}
vik_track_get_total_elevation_gain (trk, &up, &down );
for (ii = 0; ii < G_N_ELEMENTS(tracks_stats); ii++) {
tracks_stats[ii].elev_gain += up;
tracks_stats[ii].elev_loss += down;
}
if ( trk->trackpoints && VIK_TRACKPOINT(trk->trackpoints->data)->timestamp ) {
time_t t1, t2;
t1 = VIK_TRACKPOINT(g_list_first(trk->trackpoints)->data)->timestamp;
t2 = VIK_TRACKPOINT(g_list_last(trk->trackpoints)->data)->timestamp;
// Assume never actually have a track with a time of 0 (1st Jan 1970)
for (ii = 0; ii < G_N_ELEMENTS(tracks_stats); ii++) {
if ( tracks_stats[ii].start_time == 0)
tracks_stats[ii].start_time = t1;
if ( tracks_stats[ii].end_time == 0)
tracks_stats[ii].end_time = t2;
}
// Initialize to the first value
for (ii = 0; ii < G_N_ELEMENTS(tracks_stats); ii++) {
if (t1 < tracks_stats[ii].start_time)
tracks_stats[ii].start_time = t1;
if (t2 > tracks_stats[ii].end_time)
tracks_stats[ii].end_time = t2;
}
for (ii = 0; ii < G_N_ELEMENTS(tracks_stats); ii++) {
tracks_stats[ii].duration = tracks_stats[ii].duration + (int)(t2-t1);
}
}
}
