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41 #include "gromacs/math/vec.h"
42 #include "gromacs/random/random.h"
43 #include "gromacs/statistics/statistics.h"
44 #include "gromacs/utility/real.h"
45 #include "gromacs/utility/smalloc.h"
47 static void horizontal()
52 real y, a, b, da, db, aver, sigma, error, chi2, R, *xh, *yh;
55 rng = gmx_rng_init(13);
56 straight = gmx_stats_init();
57 for (i = 0; (i < n); i++)
59 y = gmx_rng_uniform_real(rng);
60 if ((ok = gmx_stats_add_point(straight, i, y, 0, 0)) != estatsOK)
62 fprintf(stderr, "%s\n", gmx_stats_message(ok));
66 if ((ok = gmx_stats_get_ase(straight, &aver, &sigma, &error)) != estatsOK)
68 fprintf(stderr, "%s\n", gmx_stats_message(ok));
70 fp = fopen("straight.xvg", "w");
71 if ((ok = gmx_stats_dump_xy(straight, fp)) != estatsOK)
73 fprintf(stderr, "%s\n", gmx_stats_message(ok));
76 printf("Horizontal line: average %g, sigma %g, error %g\n", aver, sigma, error);
77 if ((ok = gmx_stats_done(straight)) != estatsOK)
79 fprintf(stderr, "%s\n", gmx_stats_message(ok));
87 int i, dy, ok, n = 1000;
88 real y, a, b, da, db, aver, sigma, error, chi2, R, rfit;
89 const real a0 = 0.23, b0 = 2.7;
92 for (dy = 0; (dy < 2); dy++)
94 rng = gmx_rng_init(13);
95 line = gmx_stats_init();
96 for (i = 0; (i < n); i++)
98 y = a0*i+b0+50*(gmx_rng_uniform_real(rng)-0.5);
99 if ((ok = gmx_stats_add_point(line, i, y, 0, dy*0.1)) != estatsOK)
101 fprintf(stderr, "%s\n", gmx_stats_message(ok));
104 /* Line with slope test */
105 if ((ok = gmx_stats_get_ab(line, elsqWEIGHT_NONE, &a, &b, &da, &db, &chi2, &rfit)) != estatsOK)
107 fprintf(stderr, "%s\n", gmx_stats_message(ok));
109 if ((ok = gmx_stats_get_corr_coeff(line, &R)) != estatsOK)
111 fprintf(stderr, "%s\n", gmx_stats_message(ok));
115 fp = fopen("line0.xvg", "w");
119 fp = fopen("line1.xvg", "w");
121 if ((ok = gmx_stats_dump_xy(line, fp)) != estatsOK)
123 fprintf(stderr, "%s\n", gmx_stats_message(ok));
126 printf("Line with eqn. y = %gx + %g with noise%s\n", a0, b0,
127 (dy == 0) ? "" : " and uncertainties");
128 printf("Found: a = %g +/- %g, b = %g +/- %g\n", a, da, b, db);
129 if ((ok = gmx_stats_done(line)) != estatsOK)
131 fprintf(stderr, "%s\n", gmx_stats_message(ok));
133 gmx_rng_destroy(rng);
137 static void histogram()
141 int i, ok, n = 1000, norm;
142 real y, a, b, da, db, aver, sigma, error, chi2, R, *xh, *yh;
143 const real a0 = 0.23, b0 = 2.7;
147 for (norm = 0; (norm < 2); norm++)
149 rng = gmx_rng_init(13);
150 camel = gmx_stats_init();
151 for (i = 0; (i < n); i++)
153 y = sqr(gmx_rng_uniform_real(rng));
154 if ((ok = gmx_stats_add_point(camel, i, y+1, 0, 0)) != estatsOK)
156 fprintf(stderr, "%s\n", gmx_stats_message(ok));
158 y = sqr(gmx_rng_uniform_real(rng));
159 if ((ok = gmx_stats_add_point(camel, i+0.5, y+2, 0, 0)) != estatsOK)
161 fprintf(stderr, "%s\n", gmx_stats_message(ok));
165 if ((ok = gmx_stats_make_histogram(camel, 0, 101, norm, &xh, &yh)) != estatsOK)
167 fprintf(stderr, "%s\n", gmx_stats_message(ok));
169 sprintf(fn, "histo%d-data.xvg", norm);
171 gmx_stats_dump_xy(camel, fp);
173 sprintf(fn, "histo%d.xvg", norm);
175 for (i = 0; (i < 101); i++)
177 fprintf(fp, "%12g %12g\n", xh[i], yh[i]);
185 int main(int argc, char *argv[])