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39 #include "statistics.h"
45 #include "gromacs/math/vec.h"
46 #include "gromacs/random/random.h"
47 #include "gromacs/utility/real.h"
48 #include "gromacs/utility/smalloc.h"
50 static void horizontal()
55 real y, a, b, da, db, aver, sigma, error, chi2, R, *xh, *yh;
58 rng = gmx_rng_init(13);
59 straight = gmx_stats_init();
60 for (i = 0; (i < n); i++)
62 y = gmx_rng_uniform_real(rng);
63 if ((ok = gmx_stats_add_point(straight, i, y, 0, 0)) != estatsOK)
65 fprintf(stderr, "%s\n", gmx_stats_message(ok));
69 if ((ok = gmx_stats_get_ase(straight, &aver, &sigma, &error)) != estatsOK)
71 fprintf(stderr, "%s\n", gmx_stats_message(ok));
73 fp = fopen("straight.xvg", "w");
74 if ((ok = gmx_stats_dump_xy(straight, fp)) != estatsOK)
76 fprintf(stderr, "%s\n", gmx_stats_message(ok));
79 printf("Horizontal line: average %g, sigma %g, error %g\n", aver, sigma, error);
80 if ((ok = gmx_stats_done(straight)) != estatsOK)
82 fprintf(stderr, "%s\n", gmx_stats_message(ok));
90 int i, dy, ok, n = 1000;
91 real y, a, b, da, db, aver, sigma, error, chi2, R, rfit;
92 const real a0 = 0.23, b0 = 2.7;
95 for (dy = 0; (dy < 2); dy++)
97 rng = gmx_rng_init(13);
98 line = gmx_stats_init();
99 for (i = 0; (i < n); i++)
101 y = a0*i+b0+50*(gmx_rng_uniform_real(rng)-0.5);
102 if ((ok = gmx_stats_add_point(line, i, y, 0, dy*0.1)) != estatsOK)
104 fprintf(stderr, "%s\n", gmx_stats_message(ok));
107 /* Line with slope test */
108 if ((ok = gmx_stats_get_ab(line, elsqWEIGHT_NONE, &a, &b, &da, &db, &chi2, &rfit)) != estatsOK)
110 fprintf(stderr, "%s\n", gmx_stats_message(ok));
112 if ((ok = gmx_stats_get_corr_coeff(line, &R)) != estatsOK)
114 fprintf(stderr, "%s\n", gmx_stats_message(ok));
118 fp = fopen("line0.xvg", "w");
122 fp = fopen("line1.xvg", "w");
124 if ((ok = gmx_stats_dump_xy(line, fp)) != estatsOK)
126 fprintf(stderr, "%s\n", gmx_stats_message(ok));
129 printf("Line with eqn. y = %gx + %g with noise%s\n", a0, b0,
130 (dy == 0) ? "" : " and uncertainties");
131 printf("Found: a = %g +/- %g, b = %g +/- %g\n", a, da, b, db);
132 if ((ok = gmx_stats_done(line)) != estatsOK)
134 fprintf(stderr, "%s\n", gmx_stats_message(ok));
136 gmx_rng_destroy(rng);
140 static void histogram()
144 int i, ok, n = 1000, norm;
145 real y, a, b, da, db, aver, sigma, error, chi2, R, *xh, *yh;
146 const real a0 = 0.23, b0 = 2.7;
150 for (norm = 0; (norm < 2); norm++)
152 rng = gmx_rng_init(13);
153 camel = gmx_stats_init();
154 for (i = 0; (i < n); i++)
156 y = sqr(gmx_rng_uniform_real(rng));
157 if ((ok = gmx_stats_add_point(camel, i, y+1, 0, 0)) != estatsOK)
159 fprintf(stderr, "%s\n", gmx_stats_message(ok));
161 y = sqr(gmx_rng_uniform_real(rng));
162 if ((ok = gmx_stats_add_point(camel, i+0.5, y+2, 0, 0)) != estatsOK)
164 fprintf(stderr, "%s\n", gmx_stats_message(ok));
168 if ((ok = gmx_stats_make_histogram(camel, 0, 101, norm, &xh, &yh)) != estatsOK)
170 fprintf(stderr, "%s\n", gmx_stats_message(ok));
172 sprintf(fn, "histo%d-data.xvg", norm);
174 gmx_stats_dump_xy(camel, fp);
176 sprintf(fn, "histo%d.xvg", norm);
178 for (i = 0; (i < 101); i++)
180 fprintf(fp, "%12g %12g\n", xh[i], yh[i]);
188 int main(int argc, char *argv[])