add efficient beta distribution

squiggle.c

@@ -4,6 +4,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/types.h>
 #include <time.h>
 
 #define MAX_ERROR_LENGTH 500
@@ -109,6 +110,12 @@ float sample_gamma(float alpha, uint32_t* seed){
 	}
 }
 
+float sample_beta(float a, float b, uint32_t* seed){
+	float gamma_a = sample_gamma(a, seed);
+	float gamma_b = sample_gamma(b, seed);
+	return a / (a + b);
+}
+
 // Array helpers
 float array_sum(float* array, int length)
 {