benfordgenerator

commit dbf3c7ff51cf51ab4b2be0ec77a616bf92332a39
Author: nolash <dev@holbrook.no>
Date:   Mon, 29 May 2017 07:46:08 +0200

initial commit

Diffstat:
A
Makefile
 | 
13
+++++++++++++
A
src/Makefile
 | 
12
++++++++++++
A
src/benford.c
 | 
74
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
src/benford.o
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0

A
src/include/benford.h
 | 
17
+++++++++++++++++
A
src/test/Makefile
 | 
13
+++++++++++++
A
src/test/benford_test
 | 
0

A
src/test/benford_test.c
 | 
83
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

8 files changed, 212 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -0,0 +1,13 @@
+all: test
+
+dir:
+	mkdir -p .build
+
+test: libs
+	make -C src/test test
+
+libs: dir
+	make -C src libs	
+
+clean:
+	rm -rf .build
diff --git a/src/Makefile b/src/Makefile
@@ -0,0 +1,12 @@
+INCLUDE = ./include/
+BUILDDIR = ../.build
+
+libs:
+	$(CC) -Wall -g -I$(INCLUDE) -o $(BUILDDIR)/benford.o -c benford.c
+	
+#shared:
+
+#	$(CC) -Wall -I$(INCLUDE) -o lash_tree_lib.o -fPIC -c lash_tree3.c
+#	$(CC) -Wall -I$(INCLUDE) -o lash_tree_dump_lib.o -fPIC -c lash_tree3_dump.c
+#	$(CC) -shared -Wl,-soname,liblash.so.0 -o $(SHAREDOBJECTDIR)liblash.so lash_tree_lib.o lash_tree_dump_lib.o
+	
diff --git a/src/benford.c b/src/benford.c
@@ -0,0 +1,74 @@
+#include <math.h>
+#include <stdlib.h>
+
+#include "benford.h"
+
+float benford_distribution[9] = {0.16, 0.14, 0.13, 0.12, 0.11, 0.10, 0.09, 0.08, 0.07};
+
+void benford_setLead_(long int* subject, int lead) {
+	char order;
+	float norm;
+	
+	order = (int)log10(*subject);
+	norm = (int)(*subject / (float)pow(10, order));
+	*subject -= norm * pow(10, order);
+	*subject += lead * pow(10, order);
+}
+
+int benford_set(benford_t* bf, long int* number) {
+	int lead;
+	
+	lead = benford_nextLead_(bf);
+	benford_setLead_(number, lead + 1);
+	
+	return 0;
+}
+
+int benford_nextLead_(benford_t* bf) {
+	int i;
+	float ratio;
+	
+	for (i = 0; i < 9; i++) {
+		
+		ratio = bf->counts[i] / (bf->total + 1.f);
+		if (ratio < benford_distribution[i]) {
+			bf->counts[i]++;
+			bf->total++;
+			return i;
+		}
+	}
+	
+	return -1;
+}
+
+/**
+ * \fn benford_t* benford_new()
+ * \brief Constructs a new benford number distribution generator
+ */
+benford_t* benford_new() {
+	benford_t* bf;
+	int i;
+	
+	bf = malloc(sizeof(benford_t));
+	
+	if (bf == NULL) {
+		return 0;
+	}
+	for (i = 0; i < 9; i++) {
+		bf->counts[i] = 0;
+	}
+	
+	bf->total = 0;
+	
+	return bf;
+}
+
+/**
+ * \fn benford_t* benford_free()
+ * \brief Free up resources from distribution generator
+ */
+void benford_free(benford_t* bf) {
+	if (bf != NULL) {
+		free(bf);
+	}
+}
diff --git a/src/benford.o b/src/benford.o
Binary files differ.
diff --git a/src/include/benford.h b/src/include/benford.h
@@ -0,0 +1,17 @@
+#ifndef BENFORD_H_
+#define BENFORD_H_
+
+typedef struct benford {
+	char counts[9];
+	int total;
+} benford_t;
+
+benford_t* benford_new();
+void benford_free(benford_t* bf);
+int benford_set(benford_t* bf, long int* number);
+
+// private functions
+void benford_setLead_(long int* subject, int lead);
+int benford_nextLead_(benford_t* bf);
+
+#endif // BENFORD_H_
diff --git a/src/test/Makefile b/src/test/Makefile
@@ -0,0 +1,13 @@
+INCLUDE = ../include/
+BUILDDIR = ../../.build
+
+test: 
+	$(CC) -Wall -g -I$(INCLUDE) -o $(BUILDDIR)/benford_test.o -c benford_test.c
+	$(CC) -Wall -o benford_test $(BUILDDIR)/benford.o $(BUILDDIR)/benford_test.o -lm
+	
+#shared:
+
+#	$(CC) -Wall -I$(INCLUDE) -o lash_tree_lib.o -fPIC -c lash_tree3.c
+#	$(CC) -Wall -I$(INCLUDE) -o lash_tree_dump_lib.o -fPIC -c lash_tree3_dump.c
+#	$(CC) -shared -Wl,-soname,liblash.so.0 -o $(SHAREDOBJECTDIR)liblash.so lash_tree_lib.o lash_tree_dump_lib.o
+	
diff --git a/src/test/benford_test b/src/test/benford_test
Binary files differ.
diff --git a/src/test/benford_test.c b/src/test/benford_test.c
@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "benford.h"
+
+#define TESTCOUNT 100
+
+int setLead() {
+	long int t = 123456;
+	int d = 4;
+	benford_setLead_(&t, d);
+	
+	if (t != 323456) {
+		return -1;
+	}
+	
+	return 0;
+}
+
+void getSequence(char *leads, int count) {
+	int i;
+	benford_t* bf = benford_new();
+	for (i = 0; i < count; i++) {
+		*(leads+i) = benford_nextLead_(bf);
+	}
+	benford_free(bf);
+}
+
+int getLeads(int count) {
+	int i;
+	char *res = calloc(sizeof(int), count);
+	int *rescount = calloc(sizeof(int), 9);
+	
+	getSequence(res, count);
+	
+	for (i = 0; i < count; i++) {
+		(*(rescount + (*(res+i))))++;
+	}
+	for (i = 0; i < 9; i++) {
+		printf("%i: %i\n", i, *(rescount+i));
+	}
+	return 0;
+}
+
+int getNumbers(int count) {
+	int i;
+	
+	long int min = 123;
+	long int max = 912346789;
+	
+	char* leads = malloc(sizeof(char) * count);
+	getSequence(leads, count);
+	
+	benford_t* bf = benford_new();
+	
+	for (i = 0; i < TESTCOUNT; i++) {
+		long int n = (rand() % (max - min)) + min + 1;
+		long int r = n;
+		benford_set(bf, &r);
+		printf("%i: [%i?] %li -> %li\n", i, *(leads+i) + 1, n, r);
+	}
+	
+	benford_free(bf);
+	return 0;
+}
+
+int main() {
+	int e;
+	
+	srand(clock());
+	
+	if ((e = setLead()) > 0) {
+		return e;
+	}
+	if ((e = getLeads(TESTCOUNT)) > 0) {
+		return e;
+	}
+	if ((e = getNumbers(TESTCOUNT)) > 0) {
+		return e;
+	} 
+	return 0;
+}