readme tweaks; add 90% histogram function

This commit is contained in:
NunoSempere 2024-01-31 15:15:56 +01:00
parent e62a840625
commit c676a22ba8
2 changed files with 87 additions and 1 deletions

View File

@ -401,6 +401,8 @@ Overall, I'd describe the error handling capabilities of this library as pretty
### To do ### To do
- [ ] Come up with a better headline example; fermi paradox paper is too complicated
- [ ] Post on suckless subreddit
- [ ] Drive in a few more real-life applications - [ ] Drive in a few more real-life applications
- [ ] US election modelling? - [ ] US election modelling?
- [ ] Look into using size_t instead of int for sample numbers - [ ] Look into using size_t instead of int for sample numbers

View File

@ -215,8 +215,8 @@ void array_print_stats(double xs[], int n){
void array_print_histogram(double* xs, int n_samples, int n_bins) { void array_print_histogram(double* xs, int n_samples, int n_bins) {
// Interface inspired by <https://github.com/red-data-tools/YouPlot>
// Generated with the help of an llm; there might be subtle off-by-one errors // Generated with the help of an llm; there might be subtle off-by-one errors
// interface inspired by <https://github.com/red-data-tools/YouPlot>
if (n_bins <= 1) { if (n_bins <= 1) {
fprintf(stderr, "Number of bins must be greater than 1.\n"); fprintf(stderr, "Number of bins must be greater than 1.\n");
return; return;
@ -305,6 +305,90 @@ void array_print_histogram(double* xs, int n_samples, int n_bins) {
free(bins); free(bins);
} }
void array_print_90_ci_histogram(double* xs, int n){
// Code duplicated from previous function
// I'll consider simplifying it at some future point
// Possible ideas:
// - having only one function that takes any confidence interval?
// - having a utility function that is called by both functions?
ci ci_90 = array_get_90_ci(xs, n);
if (n_bins <= 1) {
fprintf(stderr, "Number of bins must be greater than 1.\n");
return;
} else if (n_samples <= 10) {
fprintf(stderr, "Number of samples must be higher than 10.\n");
return;
}
int *bins = (int*) calloc((size_t)n_bins, sizeof(int));
if (bins == NULL) {
fprintf(stderr, "Memory allocation for bins failed.\n");
return;
}
double min_value = ci_90.low, max_value = ci_90.high;
// Avoid division by zero for a single unique value
if (min_value == max_value) {
max_value++;
}
// Calculate bin width
double range = max_value - min_value;
double bin_width = range / n_bins;
// Fill the bins with sample counts
for (int i = 0; i < n_samples; i++) {
if((x[i] > min_value) && (x[i] < max_value)){
int bin_index = (int)((xs[i] - min_value) / bin_width);
if (bin_index == n_bins) {
bin_index--; // Last bin includes max_value
}
bins[bin_index]++;
}
}
// Calculate the scaling factor based on the maximum bin count
int max_bin_count = 0;
for (int i = 0; i < n_bins; i++) {
if (bins[i] > max_bin_count) {
max_bin_count = bins[i];
}
}
const int MAX_WIDTH = 50; // Adjust this to your terminal width
double scale = max_bin_count > MAX_WIDTH ? (double)MAX_WIDTH / max_bin_count : 1.0;
// Print the histogram
for (int i = 0; i < n_bins; i++) {
double bin_start = min_value + i * bin_width;
double bin_end = bin_start + bin_width;
int decimalPlaces = 1;
if((0 < bin_width) && (bin_width < 1)){
int magnitude = (int) floor(log10(bin_width));
decimalPlaces = -magnitude;
decimalPlaces = decimalPlaces > 10 ? 10 : decimalPlaces;
}
printf(" [%*.*f, %*.*f", 4+decimalPlaces, decimalPlaces, bin_start, 4+decimalPlaces, decimalPlaces, bin_end);
char interval_delimiter = ')';
if(i == (n_bins-1)){
interval_delimiter = ']'; // last bucket is inclusive
}
printf("%c: ", interval_delimiter);
int marks = (int)(bins[i] * scale);
for (int j = 0; j < marks; j++) {
printf("");
}
printf(" %d\n", bins[i]);
}
// Free the allocated memory for bins
free(bins);
}
// Replicate some of the above functions over samplers // Replicate some of the above functions over samplers
// However, in the future I'll delete this // However, in the future I'll delete this
// There should be a clear boundary between working with samplers and working with an array of samples // There should be a clear boundary between working with samplers and working with an array of samples