From 36576604878af86d8c79e2dfa7223cb80c2904b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20El=20Kharroubi?=
<michael.el-kharroubi@etu.unige.ch>
Date: Sun, 1 Nov 2020 23:18:22 +0100
Subject: [PATCH] Add comments
---
C/main.c | 12 +++++++-
C/vector.c | 68 +++++++++++++++++++++++++++++++++++-----------
C/vector.h | 60 +++++++++++++++++++++++++++++++++-------
Python/load_vec.py | 45 ++++++++++++++++++++++++++----
4 files changed, 152 insertions(+), 33 deletions(-)
diff --git a/C/main.c b/C/main.c
index 2f8891a..e1a7fcf 100644
--- a/C/main.c
+++ b/C/main.c
@@ -3,20 +3,30 @@
#include "vector.h"
+/** @brief
+ * An exemple of mathematical function
+ * in 1 dimension.
+ *
+ * @param x A double variable.
+ * @return f(x) = 2.0*sin(x) - 3.0*cos(x)
+ */
double my_function(double x)
{
- // 2.0*sin(x) - 3.0*cos(x)
return 2.0 * sin(x) - 3.0 * cos(x);
}
int main()
{
+ // Create a vector X = [0,1,2...99]
double_vector_t *X = iota(100);
+ // Create a vector Y = my_function(x)
double_vector_t *Y = apply_function(X, my_function);
+ // Export our vectors into files
export_vector("../X.vec", X);
export_vector("../Y.vec", Y);
+ // Free our vectors
destroy_vector(&Y);
destroy_vector(&X);
}
\ No newline at end of file
diff --git a/C/vector.c b/C/vector.c
index d8b58e8..431f1cf 100644
--- a/C/vector.c
+++ b/C/vector.c
@@ -3,7 +3,27 @@
#include "vector.h"
-double_vector_t *init_vector(uint_t N)
+/** @brief
+ * Compute the endianness used by
+ * the architecture.
+ *
+ * @return 1 if little-endian, 0 if big-endian
+ */
+uint8_t get_endianness()
+{
+ uint32_t endianness = 0x01020304;
+ // Return the endianness by accessing the first byte in memory
+ // which should be 1 if big-endian and 4 if little-endian
+ return *((uint8_t *)(&endianness)) == 4;
+}
+
+/** @brief
+ * Create a vector of a given dimension.
+ *
+ * @param N The number of dimensions.
+ * @return A dynamically allocated vector
+ */
+double_vector_t *init_vector(uint32_t N)
{
double_vector_t *vec = malloc(sizeof(double_vector_t));
vec->components = malloc(N * sizeof(double));
@@ -15,40 +35,52 @@ double_vector_t *init_vector(uint_t N)
}
return vec;
}
-double_vector_t *iota(uint_t N)
+/** @brief
+ * Create a vector of a given dimension,
+ * with values from 0 to N excluded.
+ *
+ * @param N The number of dimensions.
+ * @return A dynamically allocated vector : [0,1..N]
+ */
+double_vector_t *iota(uint32_t N)
{
double_vector_t *vec = init_vector(N);
- for (uint_t i = 0; i < N; i++)
+ for (uint32_t i = 0; i < N; i++)
{
vec->components[i] = i;
}
return vec;
}
+/** @brief
+ * Apply a 1d function element-wise
+ * to a given vector, and return the
+ * result in a new vector.
+ *
+ * @param vec The argument vector
+ * @param f The 1d function to apply
+ * @return A dynamically allocated vector : f(X)
+ */
double_vector_t *apply_function(double_vector_t *vec, double_function_t f)
{
double_vector_t *res = init_vector(vec->N);
- for (uint_t i = 0; i < vec->N; i++)
+ for (uint32_t i = 0; i < vec->N; i++)
{
res->components[i] = f(vec->components[i]);
}
return res;
}
-void fill_vector(double_vector_t *vec, double value)
-{
- for (uint_t i = 0; i < vec->N; i++)
- {
- vec->components[i] = value;
- }
-}
+/** @brief
+ * Export a vector into a file.
+ *
+ * @param filename The name of the output file
+ * @param vec The vector to export
+ */
void export_vector(const char *filename, double_vector_t *vec)
{
FILE *output = fopen(filename, "w");
- uint_t endianness = 0x01020304;
vector_metadata_t metadata;
- // Return the endianness by accessing the first byte in memory
- // which should be 1 if big-endian and 4 if little-endian
- metadata.endianness = *((byte_t *)(&endianness)) == 4;
+ metadata.endianness = get_endianness();
metadata.size_of_a_component = sizeof(double);
metadata.number_of_component = vec->N;
@@ -60,7 +92,11 @@ void export_vector(const char *filename, double_vector_t *vec)
fclose(output);
}
-
+/** @brief
+ * Free a vector.
+ *
+ * @param vec A double pointer on a vector
+ */
void destroy_vector(double_vector_t **vec)
{
free((*vec)->components);
diff --git a/C/vector.h b/C/vector.h
index 04a80e0..4b391f4 100644
--- a/C/vector.h
+++ b/C/vector.h
@@ -1,22 +1,62 @@
-typedef unsigned int uint_t;
-typedef unsigned char byte_t;
+#include <stdint.h>
+
typedef struct double_vector
{
- uint_t N;
+ uint32_t N; // The dimmension of the vector
double *components;
} double_vector_t;
+// Function pointer, example : double f(double x);
typedef double (*double_function_t)(double);
+/*
+* The attribute "packed" tells the compiler,
+* that the struct should be stored in memory
+* without padding. It's highly recommended,
+* if we want to serialize the structure.
+* (for example to store it in a file)
+*/
typedef struct vector_metadata
{
- byte_t endianness; // 1 = little, 0 = big
- byte_t size_of_a_component; // in bytes
- uint_t number_of_component;
+ uint8_t endianness; // 1 = little, 0 = big
+ uint8_t size_of_a_component; // in bytes
+ uint32_t number_of_component;
} __attribute__((packed)) vector_metadata_t;
-double_vector_t *init_vector(uint_t N);
-double_vector_t *iota(uint_t N);
+/** @brief
+ * Create a vector of a given dimension.
+ *
+ * @param N The number of dimensions.
+ * @return A dynamically allocated vector
+ */
+double_vector_t *init_vector(uint32_t N);
+/** @brief
+ * Create a vector of a given dimension,
+ * with values from 0 to N excluded.
+ *
+ * @param N The number of dimensions.
+ * @return A dynamically allocated vector : [0,1..N]
+ */
+double_vector_t *iota(uint32_t N);
+/** @brief
+ * Apply a 1d function element-wise
+ * to a given vector, and return the
+ * result in a new vector.
+ *
+ * @param vec The argument vector
+ * @param f The 1d function to apply
+ * @return A dynamically allocated vector : f(X)
+ */
double_vector_t *apply_function(double_vector_t *vec, double_function_t f);
-void fill_vector(double_vector_t *vec, double value);
-void export_vector(const char *file, double_vector_t *vec);
+/** @brief
+ * Export a vector into a file.
+ *
+ * @param filename The name of the output file
+ * @param vec The vector to export
+ */
+void export_vector(const char *filename, double_vector_t *vec);
+/** @brief
+ * Free a vector.
+ *
+ * @param vec A double pointer on a vector
+ */
void destroy_vector(double_vector_t **vec);
\ No newline at end of file
diff --git a/Python/load_vec.py b/Python/load_vec.py
index 400f85c..70b5d5f 100644
--- a/Python/load_vec.py
+++ b/Python/load_vec.py
@@ -1,16 +1,49 @@
import numpy as np
+from typing import Tuple
+METADATA_SIZE = 6
+
+
+def _parse_metada(metadata: bytes) -> Tuple[type, int]:
+ """
+ Parse the metadata for a vec file.
+
+ Parameters:
+ metadata (bytes): The metadata bytes
+
+ Returns:
+ (type, int): The type and the number of component of the vector
+ """
+
+ little_endian = bool(metadata[0])
+ endianness = 'little' if little_endian else 'big'
+
+ size_of_components = int(metadata[1])
+ # For now we only consider two types
+ datatype = np.float64 if size_of_components == 8 else np.float
+
+ # Recover our 32 bit integer specifying the endianness
+ nb_components = int.from_bytes(metadata[2:], endianness)
+
+ return datatype, nb_components
def load_vector(filename: str) -> np.ndarray:
+ """
+ Load a vector from a file.
+
+ Parameters:
+ filename (str): The name of the file containing the vector
+
+ Returns:
+ np.ndarray: The vector
+
+ """
file = open(filename, 'rb')
- header = file.read(6)
+ # Read our metadata struct
+ metadata = file.read(METADATA_SIZE)
- little_endian = bool(header[0])
- size_of_components = int(header[1])
- nb_components = int.from_bytes(
- header[2:], 'little' if little_endian else 'big')
+ datatype, nb_components = _parse_metada(metadata)
- datatype = np.float64 if size_of_components == 8 else np.float
array = np.fromfile(file, dtype=datatype, count=nb_components)
file.close()
--
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