First commit example of C export and matplolib plot

.gitignore

+*.vec
+.vscode
+__pycache__
+example
+*.o
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C/main.c

+#include <stdio.h>
+#include <math.h>
+
+#include "vector.h"
+
+double my_function(double x)
+{
+    // 2.0*sin(x) - 3.0*cos(x)
+    return 2.0 * sin(x) - 3.0 * cos(x);
+}
+
+int main()
+{
+    double_vector_t *X = iota(100);
+    double_vector_t *Y = apply_function(X, my_function);
+
+    export_vector("../X.vec", X);
+    export_vector("../Y.vec", Y);
+
+    destroy_vector(&Y);
+    destroy_vector(&X);
+}
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C/makefile

+
+CC=gcc -std=gnu11 -Wall -Wextra -g -fsanitize=leak -fsanitize=undefined
+LIBS=-lm
+
+example: vector.o vector.h main.c
+	$(CC) $^ $(LIBS) -o $@ 
+
+vector.o: vector.c vector.h 
+	$(CC) -c $< -o $@
+
+clean:
+	rm -f *.vec *.o example
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C/vector.c

+#include <stdio.h>
+#include <stdlib.h>
+
+#include "vector.h"
+
+double_vector_t *init_vector(uint_t N)
+{
+    double_vector_t *vec = malloc(sizeof(double_vector_t));
+    vec->components = malloc(N * sizeof(double));
+    vec->N = N;
+    if (vec == NULL)
+    {
+        perror("Can't allocate memory");
+        exit(EXIT_FAILURE);
+    }
+    return vec;
+}
+double_vector_t *iota(uint_t N)
+{
+    double_vector_t *vec = init_vector(N);
+    for (uint_t i = 0; i < N; i++)
+    {
+        vec->components[i] = i;
+    }
+    return vec;
+}
+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++)
+    {
+        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;
+    }
+}
+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.size_of_a_component = sizeof(double);
+    metadata.number_of_component = vec->N;
+
+    fwrite(&metadata, sizeof(vector_metadata_t), 1, output);
+    fwrite(vec->components,
+           metadata.size_of_a_component,
+           metadata.number_of_component,
+           output);
+
+    fclose(output);
+}
+
+void destroy_vector(double_vector_t **vec)
+{
+    free((*vec)->components);
+    free(*vec);
+    *vec = NULL;
+}
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C/vector.h

+typedef unsigned int uint_t;
+typedef unsigned char byte_t;
+typedef struct double_vector
+{
+    uint_t N;
+    double *components;
+} double_vector_t;
+typedef double (*double_function_t)(double);
+
+typedef struct vector_metadata
+{
+    byte_t endianness;          // 1 = little, 0 = big
+    byte_t size_of_a_component; // in bytes
+    uint_t number_of_component;
+} __attribute__((packed)) vector_metadata_t;
+
+double_vector_t *init_vector(uint_t N);
+double_vector_t *iota(uint_t N);
+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);
+void destroy_vector(double_vector_t **vec);
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Python/example.py

+from matplotlib import pyplot as plt
+from load_vec import load_vector
+
+X = load_vector("../X.vec")
+Y = load_vector("../Y.vec")
+
+type_of_data = 'curve'
+
+if type_of_data == 'curve':
+    plt.plot(X, Y, label="my curve")
+else:
+    plt.scatter(X, Y, marker='x', label="my points")
+
+plt.title("My data")
+plt.xlabel("X")
+plt.ylabel("Y")
+plt.legend(loc="upper right")
+
+plt.show()

Python/load_vec.py

+import numpy as np
+
+
+def load_vector(filename: str) -> np.ndarray:
+    file = open(filename, 'rb')
+    header = file.read(6)
+
+    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 = np.float64 if size_of_components == 8 else np.float
+    array = np.fromfile(file, dtype=datatype, count=nb_components)
+
+    file.close()
+    return array