altos: Add smaller pa to altitude table for TeleMini

TeleMini doesn't have space for the larger table, and the smaller one
isn't that much less accurate at lower altitudes.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/Makefile b/src/Makefile
index df7a31eefeb5c334aaeac5a90dcbef2a30be49ac..a7a26b2664755c6ee3ed5f8b4485b4808958c6bc 100644 (file)
--- a/src/Makefile
+++ b/src/Makefile
@@ -98,7 +98,7 @@ uninstall:
 
 all-recursive: all-local
 
-all-local: altitude.h altitude-pa.h ao_kalman.h ao_whiten.h $(PDCLIB)
+all-local: altitude.h altitude-pa.h altitude-pa-small.h ao_kalman.h ao_whiten.h $(PDCLIB)
 
 altitude.h: make-altitude
        nickle $< > $@
@@ -106,6 +106,9 @@ altitude.h: make-altitude
 altitude-pa.h: make-altitude-pa
        nickle $< > $@
 
+altitude-pa-small.h: make-altitude-pa
+       nickle $< --sample 3 > $@
+
 ao_kalman.h: make-kalman kalman.5c kalman_filter.5c load_csv.5c matrix.5c
        bash $< kalman > $@
 

diff --git a/src/kernel/ao_convert_pa.c b/src/kernel/ao_convert_pa.c
index fe6e0ef699b803de2b6109e088ee638ac1be0431..20162c1f5c1fea5ae5ec52b097e269344c2f4d3b 100644 (file)
--- a/src/kernel/ao_convert_pa.c
+++ b/src/kernel/ao_convert_pa.c
@@ -24,7 +24,11 @@
 #endif
 
 static const alt_t altitude_table[] AO_CONST_ATTRIB = {
+#if AO_SMALL_ALTITUDE_TABLE
+#include "altitude-pa-small.h"
+#else
 #include "altitude-pa.h"
+#endif
 };
 
 #ifndef FETCH_ALT

diff --git a/src/util/make-altitude-pa b/src/util/make-altitude-pa
index 22831d5091e8f3656dd1b7691455d8cacaf55b1a..d36f3f41de942c7726295e83ac12b39a8ca1ab7f 100644 (file)
--- a/src/util/make-altitude-pa
+++ b/src/util/make-altitude-pa
@@ -185,105 +185,135 @@ line_t best_fit(real[] values, int first, int last) {
        return (line_t) { m = m, b = b };
 }
 
-real   min_Pa = 0;
-real   max_Pa = 120000;
+void print_table (int pa_sample_shift, int pa_part_shift)
+{
+       real    min_Pa = 0;
+       real    max_Pa = 120000;
 
-/* Target is an array of < 1000 entries */
-int pa_sample_shift = 2;
-int pa_part_shift = 6;
-int pa_part_mask = (1 << pa_part_shift) - 1;
+       int pa_part_mask = (1 << pa_part_shift) - 1;
 
-int num_part = ceil(max_Pa / (2 ** (pa_part_shift + pa_sample_shift)));
+       int num_part = ceil(max_Pa / (2 ** (pa_part_shift + pa_sample_shift)));
 
-int num_samples = num_part << pa_part_shift;
+       int num_samples = num_part << pa_part_shift;
 
-real sample_to_Pa(int sample) = sample << pa_sample_shift;
+       real sample_to_Pa(int sample) = sample << pa_sample_shift;
 
-real sample_to_altitude(int sample) = pressure_to_altitude(sample_to_Pa(sample));
+       real sample_to_altitude(int sample) = pressure_to_altitude(sample_to_Pa(sample));
 
-int part_to_sample(int part) = part << pa_part_shift;
+       int part_to_sample(int part) = part << pa_part_shift;
 
-int sample_to_part(int sample) = sample >> pa_part_shift;
+       int sample_to_part(int sample) = sample >> pa_part_shift;
 
-bool is_part(int sample) = (sample & pa_part_mask) == 0;
+       bool is_part(int sample) = (sample & pa_part_mask) == 0;
 
-real[num_samples] alt = { [n] = sample_to_altitude(n) };
+       real[num_samples] alt = { [n] = sample_to_altitude(n) };
 
-int seg_len = 1 << pa_part_shift;
+       int seg_len = 1 << pa_part_shift;
 
-line_t [num_part] fit = {
-       [n] = best_fit(alt, n * seg_len, n * seg_len + seg_len - 1)
-};
-
-real[num_samples/seg_len + 1]  alt_part;
-real[dim(alt_part)]            alt_error = {0...};
-
-alt_part[0] = fit[0].b;
-alt_part[dim(fit)] = fit[dim(fit)-1].m * dim(fit) * seg_len + fit[dim(fit)-1].b;
+       line_t [num_part] fit = {
+               [n] = best_fit(alt, n * seg_len, n * seg_len + seg_len - 1)
+       };
 
-for (int i = 0; i < dim(fit) - 1; i++) {
-       real    here, there;
-       here = fit[i].m * (i+1) * seg_len + fit[i].b;
-       there = fit[i+1].m * (i+1) * seg_len + fit[i+1].b;
-#      printf ("at %d mis-fit %8.2f\n", i, there - here);
-       alt_part[i+1] = (here + there) / 2;
-}
+       real[num_samples/seg_len + 1]   alt_part;
+       real[dim(alt_part)]             alt_error = {0...};
 
-real round(real x) = floor(x + 0.5);
+       alt_part[0] = fit[0].b;
+       alt_part[dim(fit)] = fit[dim(fit)-1].m * dim(fit) * seg_len + fit[dim(fit)-1].b;
 
-real sample_to_fit_altitude(int sample) {
-       int     sub = sample // seg_len;
-       int     off = sample % seg_len;
-       line_t  l = fit[sub];
-       real r_v;
-       real i_v;
+       for (int i = 0; i < dim(fit) - 1; i++) {
+               real    here, there;
+               here = fit[i].m * (i+1) * seg_len + fit[i].b;
+               there = fit[i+1].m * (i+1) * seg_len + fit[i+1].b;
+#              printf ("at %d mis-fit %8.2f\n", i, there - here);
+               alt_part[i+1] = (here + there) / 2;
+       }
 
-       r_v = sample * l.m + l.b;
-       i_v = (round(alt_part[sub]*10) * (seg_len - off) + round(alt_part[sub+1]*10) * off) / seg_len;
-       return i_v/10;
-}
+       real round(real x) = floor(x + 0.5);
 
-real max_error = 0;
-int max_error_sample = 0;
-real total_error = 0;
+       real sample_to_fit_altitude(int sample) {
+               int     sub = sample // seg_len;
+                       int     off = sample % seg_len;
+               line_t  l = fit[sub];
+               real r_v;
+               real i_v;
 
-for (int sample = 0; sample < num_samples; sample++) {
-       real    Pa = sample_to_Pa(sample);
-       real    meters = alt[sample];
+               r_v = sample * l.m + l.b;
+               i_v = (round(alt_part[sub]*10) * (seg_len - off) + round(alt_part[sub+1]*10) * off) / seg_len;
+               return i_v/10;
+       }
 
-       real    meters_approx = sample_to_fit_altitude(sample);
-       real    error = abs(meters - meters_approx);
+       real max_error = 0;
+       int max_error_sample = 0;
+       real total_error = 0;
+
+       for (int sample = 0; sample < num_samples; sample++) {
+               real    Pa = sample_to_Pa(sample);
+               real    meters = alt[sample];
+
+               real    meters_approx = sample_to_fit_altitude(sample);
+               real    error = abs(meters - meters_approx);
+
+               int     part = sample_to_part(sample);
+
+               if (error > alt_error[part])
+                       alt_error[part] = error;
+
+               total_error += error;
+               if (error > max_error) {
+                       max_error = error;
+                       max_error_sample = sample;
+               }
+               if (false) {
+                       printf ("       %8.1f %8.2f %8.2f %8.2f %s\n",
+                               Pa,
+                               meters,
+                               meters_approx,
+                               meters - meters_approx,
+                               is_part(sample) ? "*" : "");
+               }
+       }
 
-       int     part = sample_to_part(sample);
+       printf ("/*max error %f at %7.3f kPa. Average error %f*/\n",
+               max_error, sample_to_Pa(max_error_sample) / 1000, total_error / num_samples);
 
-       if (error > alt_error[part])
-               alt_error[part] = error;
+       printf ("#define NALT %d\n", dim(alt_part));
+       printf ("#define ALT_SHIFT %d\n", pa_part_shift + pa_sample_shift);
+       printf ("#ifndef AO_ALT_VALUE\n#define AO_ALT_VALUE(x) (alt_t) (x)\n#endif\n");
 
-       total_error += error;
-       if (error > max_error) {
-               max_error = error;
-               max_error_sample = sample;
-       }
-       if (false) {
-               printf ("       %8.1f %8.2f %8.2f %8.2f %s\n",
-                       Pa,
-                       meters,
-                       meters_approx,
-                       meters - meters_approx,
-                       is_part(sample) ? "*" : "");
+       for (int part = 0; part < dim(alt_part); part++) {
+               real kPa = sample_to_Pa(part_to_sample(part)) / 1000;
+               printf ("AO_ALT_VALUE(%10.1f), /* %6.2f kPa error %6.2fm */\n",
+                       round (alt_part[part]*10) / 10, kPa,
+                       alt_error[part]);
        }
 }
 
-printf ("/*max error %f at %7.3f kPa. Average error %f*/\n",
-       max_error, sample_to_Pa(max_error_sample) / 1000, total_error / num_samples);
-
-printf ("#define NALT %d\n", dim(alt_part));
-printf ("#define ALT_SHIFT %d\n", pa_part_shift + pa_sample_shift);
-printf ("#ifndef AO_ALT_VALUE\n#define AO_ALT_VALUE(x) (alt_t) (x)\n#endif\n");
-
-for (int part = 0; part < dim(alt_part); part++) {
-       real kPa = sample_to_Pa(part_to_sample(part)) / 1000;
-       printf ("AO_ALT_VALUE(%10.1f), /* %6.2f kPa error %6.2fm */\n",
-               round (alt_part[part]*10) / 10, kPa,
-               alt_error[part]);
+autoload ParseArgs;
+
+void main()
+{
+       /* Target is an array of < 1000 entries */
+       int pa_sample_shift = 2;
+       int pa_part_shift = 6;
+
+       ParseArgs::argdesc argd = {
+               .args = {
+                       { .var = { .arg_int = &pa_sample_shift },
+                         .abbr = 's',
+                         .name = "sample",
+                         .expr_name = "sample_shift",
+                         .desc = "sample shift value" },
+                       { .var = { .arg_int = &pa_part_shift },
+                         .abbr = 'p',
+                         .name = "part",
+                         .expr_name = "part_shift",
+                         .desc = "part shift value" },
+               }
+       };
+
+       ParseArgs::parseargs(&argd, &argv);
+
+       print_table(pa_sample_shift, pa_part_shift);
 }
+
+main();