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#include <apop.h>
double row_offset;
gsl_rng *r;
void offset_rng(double *v){*v = gsl_rng_uniform(r) + row_offset;}
double find_tstat(gsl_vector *in){ return apop_mean(in)/sqrt(apop_var(in));}
double conf(double in, void *df){ return gsl_cdf_tdist_P(in, *(int *)df);}
//apop_vector_mean is a macro, so we can't point a pointer to it.
double mu(gsl_vector *in){ return apop_vector_mean(in);}
int main(){
apop_data *d = apop_data_alloc(10, 100);
r = apop_rng_alloc(3242);
for (int i=0; i< 10; i++){
row_offset = gsl_rng_uniform(r)*2 -1;
Apop_row_v(d, i, onerow);
apop_vector_apply(onerow, offset_rng);
}
size_t df = d->matrix->size2-1;
apop_data *means = apop_map(d, .fn_v = mu, .part ='r');
apop_data *tstats = apop_map(d, .fn_v = find_tstat, .part ='r');
apop_data *confidences = apop_map(tstats, .fn_dp = conf, .param = &df);
#ifndef Testing
printf("means:\n"); apop_data_show(means);
printf("\nt stats:\n"); apop_data_show(tstats);
printf("\nconfidences:\n"); apop_data_show(confidences);
#endif
//Some sanity checks, for Apophenia's test suite.
for (int i=0; i< 10; i++){
//sign of mean == sign of t stat.
assert(apop_data_get(means, i, -1) * apop_data_get(tstats, i, -1) >=0);
//inverse of P-value should be the t statistic.
assert(fabs(gsl_cdf_tdist_Pinv(apop_data_get(confidences, i, -1),100)
- apop_data_get(tstats, i, -1) < 1e-3));
}
}
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