From: Linus Torvalds Date: Thu, 8 Sep 2011 15:33:02 +0000 (-0700) Subject: Start analyzing depth profile: smoothing and time-based min/max/avg X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=2d9ac73e380ea0863119ddca4c72ea4d96327465;p=ext%2Fsubsurface.git Start analyzing depth profile: smoothing and time-based min/max/avg This turns the depth profile into a generic "plot_info" and calculates minima, maxima and averages over 1-, 2- and 3-minute intervals for each point. It also creates a smoothed version. We currently don't actually show the results, but that's the next step.. Signed-off-by: Linus Torvalds --- diff --git a/profile.c b/profile.c index 39db599..9443130 100644 --- a/profile.c +++ b/profile.c @@ -1,6 +1,7 @@ #include #include #include +#include #include #include "dive.h" @@ -23,6 +24,21 @@ struct graphics_context { double scalex, scaley; }; +/* Plot info with smoothing and one-, two- and three-minute minimums and maximums */ +struct plot_info { + int nr; + int maxtime; + struct plot_data { + int sec; + int val; + int smoothed; + int min[3]; + int max[3]; + int avg[3]; + } entry[]; +}; +#define plot_info_size(nr) (sizeof(struct plot_info) + (nr)*sizeof(struct plot_data)) + /* Scale to 0,0 -> maxx,maxy */ #define SCALE(gc,x,y) (x)*gc->maxx/gc->scalex,(y)*gc->maxy/gc->scaley @@ -218,18 +234,14 @@ static void plot_depth_text(struct dive *dive, struct graphics_context *gc) plot_text_samples(gc, sample, end); } -static void plot_depth_profile(struct dive *dive, struct graphics_context *gc) +static void plot_depth_profile(struct dive *dive, struct graphics_context *gc, struct plot_info *pi) { + int i; cairo_t *cr = gc->cr; int begins, sec, depth; - int i, samples; - struct sample *sample; + struct plot_data *entry; int maxtime, maxdepth, marker; - samples = dive->samples; - if (!samples) - return; - cairo_set_line_width(gc->cr, 2); /* Get plot scaling limits */ @@ -267,15 +279,15 @@ static void plot_depth_profile(struct dive *dive, struct graphics_context *gc) gc->scalex = maxtime; - sample = dive->sample; + entry = pi->entry; cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.80); - begins = sample->time.seconds; - move_to(gc, sample->time.seconds, sample->depth.mm); - for (i = 1; i < dive->samples; i++) { - sample++; - sec = sample->time.seconds; + begins = entry->sec; + move_to(gc, entry->sec, entry->val); + for (i = 1; i < pi->nr; i++) { + entry++; + sec = entry->sec; if (sec <= maxtime) { - depth = sample->depth.mm; + depth = entry->val; line_to(gc, sec, depth); } } @@ -444,9 +456,107 @@ static void plot_cylinder_pressure_text(struct dive *dive, struct graphics_conte } } +static void analyze_plot_info_minmax_minute(struct plot_data *entry, struct plot_data *first, struct plot_data *last, int index) +{ + struct plot_data *p = entry; + int time = entry->sec; + int seconds = 60*(index+1); + int min, max, avg, nr; + + /* Go back 'seconds' in time */ + while (p > first) { + if (p[-1].sec < time - seconds) + break; + p--; + } + + /* Then go forward until we hit an entry past the time */ + min = max = avg = p->val; + nr = 1; + while (++p < last) { + int val = p->val; + if (p->sec > time + seconds) + break; + avg += val; + nr ++; + if (val < min) + min = val; + if (val > max) + max = val; + } + entry->min[index] = min; + entry->max[index] = max; + entry->avg[index] = (avg + nr/2) / nr; +} + +static void analyze_plot_info_minmax(struct plot_data *entry, struct plot_data *first, struct plot_data *last) +{ + analyze_plot_info_minmax_minute(entry, first, last, 0); + analyze_plot_info_minmax_minute(entry, first, last, 1); + analyze_plot_info_minmax_minute(entry, first, last, 2); +} + +static struct plot_info *analyze_plot_info(struct plot_info *pi) +{ + int i; + int nr = pi->nr; + + /* Smoothing function: 5-point triangular smooth */ + for (i = 2; i < nr-2; i++) { + struct plot_data *entry = pi->entry+i; + int val; + + val = entry[-2].val + 2*entry[-1].val + 3*entry[0].val + 2*entry[1].val + entry[2].val; + entry->smoothed = (val+4) / 9; + } + + /* One-, two- and three-minute minmax data */ + for (i = 0; i < nr; i++) { + struct plot_data *entry = pi->entry +i; + analyze_plot_info_minmax(entry, pi->entry, pi->entry+nr); + } + + return pi; +} + +/* + * Create a plot-info with smoothing and ranged min/max + * + * This also makes sure that we have extra empty events on both + * sides, so that you can do end-points without having to worry + * about it. + */ +static struct plot_info *depth_plot_info(struct dive *dive) +{ + int i, nr = dive->samples + 4, sec; + size_t alloc_size = plot_info_size(nr); + struct plot_info *pi; + + pi = malloc(alloc_size); + if (!pi) + return pi; + memset(pi, 0, alloc_size); + pi->nr = nr; + sec = 0; + for (i = 0; i < dive->samples; i++) { + struct sample *sample = dive->sample+i; + struct plot_data *entry = pi->entry + i + 2; + + sec = entry->sec = sample->time.seconds; + entry->val = sample->depth.mm; + } + /* Fill in the last two entries with empty values but valid times */ + i = dive->samples + 2; + pi->entry[i].sec = sec + 20; + pi->entry[i+1].sec = sec + 40; + + return analyze_plot_info(pi); +} + static void plot(struct graphics_context *gc, int w, int h, struct dive *dive) { double topx, topy; + struct plot_info *pi = depth_plot_info(dive); topx = w / 20.0; topy = h / 20.0; @@ -466,7 +576,7 @@ static void plot(struct graphics_context *gc, int w, int h, struct dive *dive) plot_cylinder_pressure(dive, gc); /* Depth profile */ - plot_depth_profile(dive, gc); + plot_depth_profile(dive, gc, pi); /* Text on top of all graphs.. */ plot_depth_text(dive, gc);