Tutorial: NP Library Header Files

Introduction

You will learn how to create and maintain NP library header files

For this tutorial, we will create ;

• Declare all your functions in myNP_tutorial.h

• Define all your functions in myNP_tutorial.c

• Include your library in main sourceC_createHeader_example.cpp

  Don't worry about the file extension of *.cpp or *.c

  You can use either extension with Visual Studio for Numerical Programming course

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Step 1. Workspace Folder

Create local directory for programming

We will create the main directory under

C:\Users\yourID\source\repos

e.g. C:\Users\ykkim\source\repos

You can search for 'repos' in window menu

image

This is where your assignment projects should be located.

For this tutorial, let us create the new workspace directory as

• Name the directory as "NP"

  A name that clearly shows the course name

Create more necessary sub directories

Example:

• ...\...\NP\

• ...\...\NP\tutorial

• ...\...\NP\include

Step 2. Create a tutorial C Project

Under \tutorial Directory, create a new folder named as TU_CreateHeader

• i.e.: C:\Users\yourID\source\repos\NP\tutorial\TU_CreateHeader

Create a new empty project in Visual Studio Community

• Name the project as TU_createHeader

Create a new C/C++ source file for main()

• Name the source file as TU_createHeader_example.cpp

Paste the following code

// TU_createHeader_example.cpp 

#include "stdio.h"
#include "stdlib.h"

// Library include path will be modified at the end of the tutorial
// #include "myNP_tutorial.h"


void printVec(double* vec, int row);

int main(int argc, char* argv[])
{
	double x[3] = { 1, 2, 3 };
	int x_size = sizeof(x)/sizeof(double);
	printVec(x, x_size);
}


void printVec(double* vec, int size)
{
	for (int i = 0; i < size; i++)
		printf("Vector[%d] = %.1f \n", i, vec[i]);
	printf("\n");
}

Compile and Run the program. It should display the vector x[] values properly.

Step 3. Create your Header files

Under the directory of \include, create 'myNP_tutorial.cpp' and 'myNP_tutorial.h'.

• C:\Users\yourID\source\repos\NP\include

• You can paste codes below. Or You can download source files here

Do not make duplicates of library header files. Keep updating the library header file as you do assignments.

myNP_tutorial.h

/* myNP_tutorial.h */
#ifndef		_MY_NP_H		// use either (#pragma once) or  (#ifndef ...#endif)
#define		_MY_NP_H

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

extern void printVec(double* vec, int row);

#endif

myNP_tutorial.cpp

/* myNP_tutorial.cpp */

#include "myNP_tutorial.h"

void printVec(double* vec, int size)
{
	for (int i = 0; i < size; i++)
		printf("Vector[%d] = %.1f \n", i, vec[i]);
	printf("\n");
}

Your library header files, and project source files should be located as

image

Step 4. Include your Header files in VS code

1. 솔루션 탐색기(Solution Explorer) > 헤더파일 > 추가 > 기존항목

2. ../NP/Include/ 폴더에서 myNP_tutorial.h, myNP_tutorial.cpp 선택

image

3. Modify the header file include path

image

Step 5. Include your Header files in main code

In the above main() program, include your header library by finding the path.

Now, you need to delete the function definition of printVec() in main(), for we have included the function from the header library file.

The main source file should be modified as

/*  TU_createHeader_example.cpp  */

#include "stdio.h"
#include "stdlib.h"

// Change the Include path 
#include "../../include/myNP_tutorial.h"   // Find the location of header files
// #include "myNP_tutorial.h"   // if the PATH is already Included in Project


void printVec(double* vec, int row);

int main(int argc, char* argv[])
{

	double x[3] = { 1, 2, 3 };
	int x_size = sizeof(x)/sizeof(double);

	printVec(x, x_size);

}

// void printVec() definition is deleted in this file

Compile and run the program.