C / Python> Lire la valeur fwrite () en C avec Python> v0.1: 1 valeur / v0.2: 3 valeurs / v0.3: correspond à size_t / v0.4: lire le type complexe double

Environnement d'exploitation

GeForce GTX 1070 (8GB)
ASRock Z170M Pro4S [Intel Z170chipset]
Ubuntu 14.04 LTS desktop amd64
TensorFlow v0.11
cuDNN v5.1 for Linux
CUDA v8.0
Python 2.7.6
IPython 5.1.0 -- An enhanced Interactive Python.
gcc (Ubuntu 4.8.4-2ubuntu1~14.04.3) 4.8.4

Je souhaite afficher une image du coefficient généré par le code C ++ avec Jupyter / matplotlib. Pour ce faire, je lirais probablement le résultat C fwrite () en Python.

J'ai essayé de le mettre en œuvre.

v0.1 (1 valeur)

C (write)

writeTest.c

#include <stdio.h>
#include <stdlib.h>

int main(void){
	FILE *wfp;
	float pi = 3.141592;

	wfp = fopen("sample.bin","wb");
	fwrite(&pi, sizeof(float), 1, wfp);
	fclose(wfp);
}

Python (read)

Référence http://stackoverflow.com/questions/2146031/what-is-the-equivalent-of-fread-from-matlab-in-python

readTest.py

import numpy as np
import array

with open("sample.bin") as rfp:
	a = array.array("f") # f: typecode for float
	a.fromfile(rfp, 1)
	print (a)

Le code de type ci-dessus est basé sur ce qui suit. https://docs.python.org/3.1/library/array.html

Courir

Génération sample.bin

$ gcc writeTest.c && ./a.out

lire sample.bin

$ python readTest.py 
array('f', [3.141592025756836]) 

Je lis.

v0.2 (3 valeurs)

C (write)

writeTest.c

#include <stdio.h>
#include <stdlib.h>

int main(void){
	FILE *wfp;
	float pi = 3.141592;
	float napier = 2.718;
	float avogadro1 = 6.022;

	wfp = fopen("sample.bin","wb");
	fwrite(&pi, sizeof(float), 1, wfp);
	fwrite(&napier, sizeof(float), 1, wfp);
	fwrite(&avogadro1, sizeof(float), 1, wfp);
	fclose(wfp);
}

Python (read)

readTest.py

import numpy as np
import array

with open("sample.bin","rb") as rfp:
	a = array.array("f") # f: typecode for float
	a.fromfile(rfp, 3)
	print (a)

Courir

Génération sample.bin

$ gcc writeTest.c && ./a.out

lire sample.bin

$ python readTest.py 
array('f', [3.141592025756836, 2.7179999351501465, 6.021999835968018])

compatible v0.3 (size_t)

(Ajout 2016/12/19)

Je trébuchais en lisant le type size_t. v0.1 @ http://qiita.com/7of9/items/68673ac3239532064c28

type size_t

sizeofPrint.c

#include <stdio.h>
#include <stdlib.h>

int main(void) {
	printf("%ld\n", sizeof(size_t));
	printf("%ld\n", sizeof(int));
}

Courir

$ gcc sizeofPrint.c && ./a.out 
8
4

Dans cet environnement, size_t vaut 8.

C (write)

writeTest.c

#include <stdio.h>
#include <stdlib.h>

int main(void){
	FILE *wfp;
	size_t pi = 314;
	float napier = 2.718;
	float avogadro1 = 6.022;

	wfp = fopen("sample.bin","wb");
	fwrite(&pi, sizeof(size_t), 1, wfp);
	fwrite(&napier, sizeof(float), 1, wfp);
	fwrite(&avogadro1, sizeof(float), 1, wfp);
	fclose(wfp);
}

Python (read)

Pour lire la valeur de size_t (sizeof () = 8) côté Python, ce serait du type [unsigned long].

https://docs.python.org/3.1/library/array.html Selon «L»

readTest.py

import numpy as np
import array

with open("sample.bin","rb") as rfp:
	szv = array.array("L") # L: typecodef for [unsigned long]
	szv.fromfile(rfp, 1)
	print (szv)
	flv = array.array("f") # f: typecode for float
	flv.fromfile(rfp, 2)
	print (flv)

Courir

$ python readTest.py 
array('L', [314L])
array('f', [2.7179999351501465, 6.021999835968018])

v0.4 (lecture complexe double)

(Ajout 2016/12/20)

Comment lire le type double complexe? Je le lis comme un double type pour le moment.

C (write)

Elle est différente de la valeur réelle du nombre Abogadro, mais pour le moment.

writeTest.c

#include <stdio.h>
#include <stdlib.h>
#include <complex.h>

int main(void){
	FILE *wfp;
	size_t pi = 314;
	float napier = 2.718;
	double complex avogadro = 6.022 + 10.23 * I; 

	wfp = fopen("sample.bin","wb");
	fwrite(&pi, sizeof(size_t), 1, wfp);
	fwrite(&napier, sizeof(float), 1, wfp);
	fwrite(&avogadro, sizeof(double complex), 1, wfp);
	fclose(wfp);
}

Python (read)

readTest.py

import numpy as np
import array

with open("sample.bin","rb") as rfp:
	szv = array.array("L") # L: typecodef for [unsigned long]
	szv.fromfile(rfp, 1)
	print (szv)
	napier = array.array("f") # f: typecode for float
	napier.fromfile(rfp, 1)
	print (napier)
	avogadro = array.array("d") # d: typecode for double
	avogadro.fromfile(rfp, 2) # real and imaginary part of the complex number
	print (avogadro)

Courir

$ gcc writeTest.c && ./a.out
$ python readTest.py 
array('L', [314L])
array('f', [2.7179999351501465])
array('d', [6.022, 10.23])

Pour l'instant, j'ai pu lire la partie réelle et la partie imaginaire du double complexe. Est-ce une méthode comme la conversion en un type complexe basé sur les deux valeurs?