rename sampler functions, elaborate on README, etc.

README.md

@@ -1,15 +1,30 @@
 # Squiggle.c
 
-
+A self-contained C99 library that provides a subset of [Squiggle](https://www.squiggle-language.com/)'s functionality in C.
 
 ## Why C?
 
 - Because it is fast
-- Because it can be made faster if need be, e.g., with a multi-threading library like OpenMP
-- Because if you can implement something in C, you can implement it anywhere else
-- Because it will last long
-- Because the language is honest
 - Because I enjoy it
+- Because C is honest
+- Because it will last long
+- Because it can fit in my head
+- Because if you can implement something in C, you can implement it anywhere else
+- Because it can be made faster if need be, e.g., with a multi-threading library like OpenMP, or by adding more algorithmic complexity
+
+## The core scheme
+
+Have some basic building blocks, like , and return samplers. Use previous samplers to . Then use the final sampler to produce an array of samples.
+
+## Getting started
+
+You can follow some example usage in the examples/ folder
+
+1. In the first example, we define a small model, and draw one sample from it
+2. In the second example, we define a small model, and return many samples
+3. In the third example, we use a gcc extension—nested functions—to rewrite the code from point 2. in a more linear way.
+4. In the fourth example, we define some simple cdfs, and we draw samples from those cdfs. We see that this approach is slower than using the built-in samplers, e.g., the normal sampler.
+5. In the fifth example, we define the cdf for the beta distribution, and we draw samples from it. 
 
 ## To do list
 

examples/04_sample_from_cdf_simple/example.c

@@ -54,7 +54,7 @@ void test_and_time_sampler_float(char* cdf_name, float cdf_float(float), uint32_
     printf("\nGetting some samples from %s:\n", cdf_name);
     clock_t begin = clock();
     for (int i = 0; i < NUM_SAMPLES; i++) {
-        struct box sample = sampler_float_cdf(cdf_float, seed);
+        struct box sample = sampler_cdf_float(cdf_float, seed);
         if (sample.empty) {
             printf("Error in sampler function for %s", cdf_name);
         } else {

examples/04_sample_from_cdf_simple/makefile

@@ -19,7 +19,7 @@ DEPENDENCIES=$(MATH)
 
 ## Flags
 DEBUG= #'-g'
-STANDARD=-std=gnu99 ## allows for nested functions.
+STANDARD=-std=c99 ## gnu99 allows for nested functions.
 EXTENSIONS= #-fnested-functions
 WARNINGS=-Wall
 OPTIMIZED=-O3#-Ofast

examples/05_sample_from_cdf_beta/example.c

@@ -136,7 +136,7 @@ void test_and_time_sampler_box(char* cdf_name, struct box cdf_box(float), uint32
     printf("\nGetting some samples from %s:\n", cdf_name);
     clock_t begin = clock();
     for (int i = 0; i < NUM_SAMPLES; i++) {
-        struct box sample = sampler_box_cdf(cdf_box, seed);
+        struct box sample = sampler_cdf_box(cdf_box, seed);
         if (sample.empty) {
             printf("Error in sampler function for %s", cdf_name);
         } else {

examples/05_sample_from_cdf_beta/makefile

@@ -19,7 +19,7 @@ DEPENDENCIES=$(MATH)
 
 ## Flags
 DEBUG= #'-g'
-STANDARD=-std=gnu99 ## allows for nested functions.
+STANDARD=-std=c99 ## gnu99 allows for nested functions.
 EXTENSIONS= #-fnested-functions
 WARNINGS=-Wall
 OPTIMIZED=-O3#-Ofast

squiggle.c

@@ -22,7 +22,7 @@
     } while (0)
 
 // PI constant
-const float PI = M_PI; // 3.14159265358979323846;
+const float PI = 3.14159265358979323846; // M_PI in gcc gnu99
 
 // Pseudo Random number generator
 

squiggle.h

@@ -4,29 +4,15 @@
 // uint32_t header
 #include <stdint.h>
 
-// Macros
-#define EXIT_ON_ERROR 0
-#define MAX_ERROR_LENGTH 500
-#define PROCESS_ERROR(...)                                                              \
-    do {                                                                                \
-        if (EXIT_ON_ERROR) {                                                            \
-            printf("@, in %s (%d)", __FILE__, __LINE__);                                \
-            exit(1);                                                                    \
-        } else {                                                                        \
-            char error_msg[MAX_ERROR_LENGTH];                                           \
-            snprintf(error_msg, MAX_ERROR_LENGTH, "@, in %s (%d)", __FILE__, __LINE__); \
-            struct box error = { .empty = 1, .error_msg = error_msg };                  \
-            return error;                                                               \
-        }                                                                               \
-    } while (0)
-
 // Pseudo Random number generator
 uint32_t xorshift32(uint32_t* seed);
 
-// Distribution & sampling functions
+// Basic distribution sampling functions
 float rand_0_to_1(uint32_t* seed);
 float rand_float(float max, uint32_t* seed);
 float unit_normal(uint32_t* seed);
+
+// Composite distribution sampling functions
 float random_uniform(float from, float to, uint32_t* seed);
 float random_normal(float mean, float sigma, uint32_t* seed);
 float random_lognormal(float logmean, float logsigma, uint32_t* seed);
@@ -46,12 +32,28 @@ struct box {
     char* error_msg;
 };
 
+// Macros to handle errors
+#define EXIT_ON_ERROR 0
+#define MAX_ERROR_LENGTH 500
+#define PROCESS_ERROR(...)                                                              \
+    do {                                                                                \
+        if (EXIT_ON_ERROR) {                                                            \
+            printf("@, in %s (%d)", __FILE__, __LINE__);                                \
+            exit(1);                                                                    \
+        } else {                                                                        \
+            char error_msg[MAX_ERROR_LENGTH];                                           \
+            snprintf(error_msg, MAX_ERROR_LENGTH, "@, in %s (%d)", __FILE__, __LINE__); \
+            struct box error = { .empty = 1, .error_msg = error_msg };                  \
+            return error;                                                               \
+        }                                                                               \
+    } while (0)
+
 // Inverse cdf
 struct box inverse_cdf_float(float cdf(float), float p);
 struct box inverse_cdf_box(struct box cdf_box(float), float p);
 
 // Samplers from cdf
-struct box sampler_box_cdf(struct box cdf(float), uint32_t* seed);
+struct box sampler_cdf_float(float cdf(float), uint32_t* seed);
-struct box sampler_float_cdf(float cdf(float), uint32_t* seed);
+struct box sampler_cdf_box(struct box cdf(float), uint32_t* seed);
 
 #endif