* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
#include <glib.h>
#include <time.h>
-#include <stdio.h>
#include <stdlib.h>
+#ifdef HAVE_STRING_H
#include <string.h>
+#endif
+#ifdef HAVE_MATH_H
#include <math.h>
+#endif
+
#include "coords.h"
#include "vikcoord.h"
#include "viktrack.h"
VikTrackpoint *vik_trackpoint_new()
{
VikTrackpoint *tp = g_malloc0(sizeof(VikTrackpoint));
- tp->extended = FALSE;
tp->speed = NAN;
tp->course = NAN;
+ tp->altitude = VIK_DEFAULT_ALTITUDE;
+ tp->hdop = VIK_DEFAULT_DOP;
+ tp->vdop = VIK_DEFAULT_DOP;
+ tp->pdop = VIK_DEFAULT_DOP;
return tp;
}
total_length = vik_track_get_length_including_gaps ( tr );
chunk_length = total_length / num_chunks;
+ /* Zero chunk_length (eg, track of 2 tp with the same loc) will cause crash */
+ if (chunk_length <= 0) {
+ g_free(pts);
+ return NULL;
+ }
+
current_dist = 0.0;
current_area_under_curve = 0;
current_chunk = 0;
dist_along_seg = chunk_length - current_dist;
if ( ignore_it || !iter->next ) {
pts[current_chunk] = current_area_under_curve / current_dist;
+ if (!iter->next) {
+ int i;
+ for (i = current_chunk + 1; i < num_chunks; i++)
+ pts[i] = pts[current_chunk];
+ break;
+ }
}
else {
current_area_under_curve += dist_along_seg * (altitude1 + (altitude2 - altitude1)*dist_along_seg/current_seg_length);
*up = *down = VIK_DEFAULT_ALTITUDE;
}
-typedef struct {
- double a, b, c, d;
-} spline_coeff_t;
-
-void compute_spline(int n, double *x, double *f, spline_coeff_t *p)
-{
- double *h, *alpha, *B, *m;
- int i;
- int orig_n = n;
- double new_x[3], new_f[3];
-
- if (n==0) return;
- if (n==1) {
- new_x[0] = x[0];
- new_f[0] = f[0];
- new_x[1] = x[0]+0.00001;
- new_f[1] = f[0];
- x = new_x;
- f = new_f;
- n = 3;
- }
- if (n==2) {
- new_x[0] = x[0];
- new_f[0] = f[0];
- new_x[1] = x[1];
- new_f[1] = f[1];
- new_x[2] = x[1] + x[1]-x[0];
- new_f[2] = f[1] + f[1]-f[0];
- x = new_x;
- f = new_f;
- n = 3;
- }
-
- /* we're solving a linear system of equations of the form Ax = B.
- * The matrix a is tridiagonal and consists of coefficients in
- * the h[] and alpha[] arrays.
- */
-
- h = (double *)malloc(sizeof(double) * (n-1));
- for (i=0; i<n-1; i++) {
- h[i] = x[i+1]-x[i];
- }
-
- alpha = (double *)malloc(sizeof(double) * (n-2));
- for (i=0; i<n-2; i++) {
- alpha[i] = 2 * (h[i] + h[i+1]);
- }
-
- /* B[] is the vector on the right hand side of the equation */
- B = (double *)malloc(sizeof(double) * (n-2));
- for (i=0; i<n-2; i++) {
- B[i] = 6 * ((f[i+2] - f[i+1])/h[i+1] - (f[i+1] - f[i])/h[i]);
- }
-
- /* Now solve the n-2 by n-2 system */
- m = (double *)malloc(sizeof(double) * (n-2));
- for (i=1; i<=n-3; i++) {
- /*
- d0 = alpha 0
- a0 = h1
- c0 = h1
-
- di = di - (ai-1 / di-1) * ci-1
- bi = bi - (ai-1 / di-1) * bi-1
- ;
- */
- alpha[i] = alpha[i] - (h[i]/alpha[i-1]) * h[i];
- B[i] = B[i] - (h[i]/alpha[i-1]) * B[i-1];
- }
- /* xn-3 = bn-3 / dn-3; */
- m[n-3] = B[n-3]/alpha[n-3];
- for (i=n-4; i>=0; i--) {
- m[i] = (B[i]-h[i+1]*m[i+1])/alpha[i];
- }
-
- for (i=0; i<orig_n-1; i++) {
- double mi, mi1;
- mi = (i==(n-2)) ? 0 : m[i];
- mi1 = (i==0) ? 0 : m[i-1];
-
- p[i].a = f[i+1];
- p[i].b = (f[i+1] - f[i]) / h[i] + h[i] * (2*mi + mi1) / 6;
- p[i].c = mi/2;
- p[i].d = (mi-mi1)/(6*h[i]);
- }
-
- free(alpha);
- free(B);
- free(h);
- free(m);
-}
/* by Alex Foobarian */
gdouble *vik_track_make_speed_map ( const VikTrack *tr, guint16 num_chunks )
{
gdouble *v, *s, *t;
- gdouble duration, chunk_dur, T, s_prev, s_now;
+ gdouble duration, chunk_dur;
time_t t1, t2;
- int i, pt_count, numpts, spline;
+ int i, pt_count, numpts, index;
GList *iter;
- spline_coeff_t *p;
if ( ! tr->trackpoints )
return NULL;
g_assert ( num_chunks < 16000 );
-#ifdef XXXXXXXXXXXXXXXXXX
- iter = tr->trackpoints;
- while (iter) {
-
- }
-#endif /*XXXXXXXXXXXXXXXXXX*/
-
t1 = VIK_TRACKPOINT(tr->trackpoints->data)->timestamp;
t2 = VIK_TRACKPOINT(g_list_last(tr->trackpoints)->data)->timestamp;
duration = t2 - t1;
return NULL;
if (duration < 0) {
- g_warning("negative duration: unsorted trackpoint timestamps?\n");
+ g_warning("negative duration: unsorted trackpoint timestamps?");
return NULL;
}
pt_count = vik_track_get_tp_count(tr);
s = g_malloc(sizeof(double) * pt_count);
t = g_malloc(sizeof(double) * pt_count);
- p = g_malloc(sizeof(spline_coeff_t) * (pt_count-1));
iter = tr->trackpoints->next;
numpts = 0;
iter = iter->next;
}
- compute_spline(numpts, t, s, p);
-
- /* the spline gives us distances at chunk_dur intervals. from these,
- * we obtain average speed in each interval.
+ /* 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.
*/
- spline = 0;
- T = t[spline];
- s_prev =
- p[spline].d * pow(T - t[spline+1], 3) +
- p[spline].c * pow(T - t[spline+1], 2) +
- p[spline].b * (T - t[spline+1]) +
- p[spline].a;
- for (i = 0; i < num_chunks; i++, T+=chunk_dur) {
- while (T > t[spline+1]) {
- spline++;
+ 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 speeds between intermediate trackpoints.
+ */
+ if (t[0] + i*chunk_dur >= t[index]) {
+ gdouble acc_t = 0, acc_s = 0;
+ numpts = 0;
+ while (t[0] + i*chunk_dur >= t[index]) {
+ acc_s += (s[index+1]-s[index]);
+ acc_t += (t[index+1]-t[index]);
+ index++;
+ numpts++;
+ }
+ v[i] = acc_s/acc_t;
+ }
+ else if (i) {
+ v[i] = v[i-1];
+ }
+ else {
+ v[i] = 0;
}
- s_now =
- p[spline].d * pow(T - t[spline+1], 3) +
- p[spline].c * pow(T - t[spline+1], 2) +
- p[spline].b * (T - t[spline+1]) +
- p[spline].a;
- v[i] = (s_now - s_prev) / chunk_dur;
- s_prev = s_now;
- /*
- * old method of averages
- v[i] = (s[spline+1]-s[spline])/(t[spline+1]-t[spline]);
- */
}
g_free(s);
g_free(t);
- g_free(p);
return v;
}
projects / andy / viking.git / blobdiff