macOS Help for writnig C++ program

[sitha]

Hi,
I am new to C++ program, Pls help me for following probelm.
I have a text file as following,
DYNAMIC ANALYSIS
次元数 ケース 内部加振　活荷重
3 1 0 0
KACC KDIS KSTS KSTN KSSR KJOT KNOD KRAT KSEC KMSS KWPR
7 7 14 14 0 14 1 0 0 1 0
FREQ GFREQ EXMAX
0.0 2.00 1.0D-6
VISCOUS BOUNDARY INFORMATION
3 2.00
77 60 11 66
0 0
加速度時刻歴出力節点番号(KACC=0.OR.>NTJの場合,削除)
1080 1254 1484 1549 1563 1592 1608
JOINT挙動出力要素番号(KJOT=0.OR.>JOINTの場合,削除)
7 8 20 22 117 118 127
128 129 130 133 134 139 140
NODES
1 -101.582 -234.742 280.000 3
2 -76.838 -234.742 280.000 3
3 -54.479 -234.742 280.000 3
4 -34.276 -234.742 280.000 3
5 -16.020 -234.742 280.000 3
6 0.476 -234.742 280.000 3
7 19.063 -234.742 280.000 3
8 37.649 -234.742 280.000 3
9 72.755 -234.742 280.000 3
10 112.781 -234.742 280.000 3
11 158.418 -234.742 280.000 3

Now I want to extract only nodes from this file and put them into another text file as follows,

101.582 -234.742 280.000
-76.838 -234.742 280.000
-54.479 -234.742 280.000
-34.276 -234.742 280.000
-16.020 -234.742 280.000
0.476 -234.742 280.000
19.063 -234.742 280.000
37.649 -234.742 280.000
72.755 -234.742 280.000
112.781 -234.742 280.000
158.418 -234.742 280.000
I should omit all the setences and other details, I only need coordinates of nodes in another text file. Pls help me how to write a program.

Regards,
Sitha.

 

[nsutt22]

What knowledge in C++ do you have? You want to use fstream. ifstream for that matter. and then go from there?

#include ifstream;

ifstream inFile;

inFile >> etc... etc...

 

[Soulstorm]

You will need to use <fstream> Read your books to learn how to do that. Next, you must think of a way to obtain only the nodes you need.

Firstly, I recommend yo read the file line-by-line. For example, I would read each line and insert it into a string (include <string> for working with STL strings). Then, I would put each string into a vector (include <vector> for working with STL vectors). When importing is finished, you will have a vector that will contain a string in each position.

At that point, you will open for access a new file, using ifstream, and you are going to write each line that doesn't contain the characters you need into it. I recommend looking at this post to find some examples. Other ways exist, though.

 

[robbieduncan]

Text processing is probably easier in Perl than C++. Is there a particular reason to use C++?

 

[Josh]

You could either use vectors (better) or arrays to do this (though many more options exist).

Here's a quick example of creating some arrays (to keep it simple), reading in your info, and then displaying the info you want.

I used the standard namespace to make things more readable.

You'd have to adjust this to make it print to a new file rather than on screen, and it has not been tested so I cannot gaurantee it works - but it should.

#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
using namespace std;

const int NODES = 50;                       // number of nodes expected

int main()
{ string filename;
  fstream nodes_file;
  float col2[NODES], col3[NODES], col4[NODES];  // stores the data you need
  string col1[NODES], col5[NODES];  // col1 and col5 trap uneeded info
  int i, good_nodes;

// set good_nodes to 0

  good_nodes = 0;

// set dummy arrays to have no values
 
  for(i=0;i<NODES;i++)
    { col1[i] = "null";
      col5[i] = "null";
    }

// begin and prompt for name

  cout << "Please enter the file name: ";
  cin >> filename;
  
// open the file

  nodes_file.open(filename.data(),ios::in);
  
// read the file into the arrays

  while(!nodes_file.eof() && !nodes_file.fail())
    { for(i=0;i<NODES;i++)
        { nodes_file >> col1[i] >> col2[i] >> col3[i]
                     >> col4[i] >> col5[i];
        }    
    }

// close the file

   nodes_file.close();

// count number of non-null entries

  for(i=0;i<NODES && col1[i] != "null";i++)
    good_nodes++;

// print nodes to screen

  cout << fixed << setprecision(3);
  
  for(i=0;i<good_nodes;i++)
    { cout >> col2[i] >> col3[i] >> col4[i] >> endl;
    }

return 0;
}

 

[dogeye]

it should work fine(at least works on my machine)

hope it helps.

#include <fstream>
#include <iostream>
#include <String>
#include <sstream>

using namespace std;

void main()
{
	char filename[15];
	bool found=false;
	string buff;
	cout<<"Enter your file name: ";
	//save the file name
	cin>>filename;                                         
	// open the input file
	ifstream input(filename);                               
	if(!input)
	{
		cout<<"can't open the file"<<endl;	
	}
	else
	{
		// open a file for output
		ofstream output;                                    
		// output file name
		output.open("nodes.txt");                           
		while(!input.eof())
		{
			getline(input,buff);
			// if the line is read as NODES
			if (buff.compare("NODES")==0)              
			{
				// start to read and output the following lines
				while(!input.eof())                   
				{
					getline(input,buff);
					istringstream tmp(buff);
					// format the output
					string first,second,third,fourth,fifth;              
					tmp>>first>>second>>third>>fourth>>fifth;
					output<<second<<" "<<third<<" "<<fourth<<endl;
				}
				found=true;
				cout<<"Nodes found and outputed"<<endl;
				break;
			}
			
		}
		output.close();
	}
	if (found==false)
		cout<<"No node found in the file"<<endl;
	input.close();
	system("pause");
}

 

[munkees]

hope it helps.

#include <fstream>
#include <iostream>
#include <String>
#include <sstream>

using namespace std;

void main()
{
	char filename[15];
	bool found=false;
	string buff;
	cout<<"Enter your file name: ";
	//save the file name
	cin>>filename;                                         
	// open the input file
	ifstream input(filename);                               
	if(!input)
	{
		cout<<"can't open the file"<<endl;	
	}
	else
	{
		// open a file for output
		ofstream output;                                    
		// output file name
		output.open("nodes.txt");                           
		while(!input.eof())
		{
			getline(input,buff);
			// if the line is read as NODES
			if (buff.compare("NODES")==0)              
			{
				// start to read and output the following lines
				while(!input.eof())                   
				{
					getline(input,buff);
					istringstream tmp(buff);
					// format the output
					string first,second,third,fourth,fifth;              
					tmp>>first>>second>>third>>fourth>>fifth;
					output<<second<<" "<<third<<" "<<fourth<<endl;
				}
				found=true;
				cout<<"Nodes found and outputed"<<endl;
				break;
			}
			
		}
		output.close();
	}
	if (found==false)
		cout<<"No node found in the file"<<endl;
	input.close();
	system("pause");
}

nice code layout, this is how C is meant to be layed out as was the code from kerni Ritchie the desginers of C. In some of there books it set out like

void function() {


if ( ...... ) {
}

}

but should be :-

void function()
{

if( .... )
{
}
}

much easier to read. I see alot of people have done the first which was put into books to save space.