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More Efficient way? Grabbing numbers

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Join Date: Apr 2009

Posts: 147

Reputation: gretty is an unknown quantity at this point

Solved Threads: 7

gretty

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Junior Poster

More Efficient way? Grabbing numbers

Jun 16th, 2009

Hi

I am reading a excel file & grabbing certain elements out of the file to store in arrays. I know how to do it, but can you tell me if there is a more efficient way to do this. This, meaning, grabbing certain elements out of a line/string.

Inside the excel the information is arrange like so. And I am grabbing the numbers in bold in each line.

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AED,0.915,0.005,0.910,0.920,0.910,0.925,0.910,318870,,76,70,0
AAC,1.520,-0.030,1.520,1.525,1.540,1.540,1.520,459155,,45,68,-1
AWL,0.003,-0.001,0.003,0.004,0.004,0.004,0.003,989216,,17500,53,-18
..........

My way of getting the information is like so, but it seems really amateurish to me

. Is there a better way to do it?

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
 
using namespace std;
 
struct stocks
{
	string stock_data[999];
	string code[999];
	float price[999];
	float purchase[999];
	float quantity[999];
};
 
int main()
{
 
	stocks current_data;
	int i = 0;
 
	ifstream infile;
 
	infile.open("Watchlists.csv");
 
	if (!infile)
	{
		cout << "Failed to open file";
		return 0;
	}
 
 
	while(infile)
	{
		getline(infile, current_data.code[i], ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile >> current_data.price[i];
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile >> current_data.quantity[i];
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, '\n');
		i++;
 
	}
 
return 0;
}
#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>

using namespace std;

struct stocks
{
	string stock_data[999];
	string code[999];
	float price[999];
	float purchase[999];
	float quantity[999];
};

int main()
{

	stocks current_data;
	int i = 0;

	ifstream infile;

	infile.open("Watchlists.csv");

	if (!infile)
	{
		cout << "Failed to open file";
		return 0;
	}

	
	while(infile)
	{
		getline(infile, current_data.code[i], ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile >> current_data.price[i];
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile >> current_data.quantity[i];
		infile.ignore(4000, ',');
		infile.ignore(4000, ',');
		infile.ignore(4000, '\n');
		i++;

	}

return 0;
}

Last edited by gretty; Jun 16th, 2009 at 1:59 am.

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Join Date: Dec 2005

Posts: 5,850

Reputation: Salem has a reputation beyond repute

Solved Threads: 749

Salem

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Void main'ers are DOOMed

Re: More Efficient way? Grabbing numbers

Jun 16th, 2009

Do you mean efficient, or elegant?

Do you mean efficient, or adaptable?

You could create (or find, there are plenty for this common exercise) a CSV class which does all the comma parsing for you.

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
while ( line.getline() ) {
  CSV parser(line);  // does all the magic of splitting a line at commas
  current_data.code[i] = parser.column(1);  // and so on
}
while ( line.getline() ) {
  CSV parser(line);  // does all the magic of splitting a line at commas
  current_data.code[i] = parser.column(1);  // and so on
}

Oh, and it's probably more useful to make an array of your struct, not have arrays inside your struct.

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Join Date: Jul 2008

Posts: 2,001

Reputation: ArkM has much to be proud of

Solved Threads: 343

ArkM

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Postaholic

Re: More Efficient way? Grabbing numbers

Jun 16th, 2009

Yet another tip:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
while (infile) // wrong loop!
{
  getline(...);
  ... >> ...
  i++
}
while (infile) // wrong loop!
{
  getline(...);
  ... >> ...
  i++
}

See what happens if the file is empty or after the last line reading:
1. infile is good so the next loop entered...
2. getline failed, all subsequent input operations are suppressed...
3. operator >> gets nothing...
4. i++ counts inexistent record...

See the simplest tokenizer in my recent post:
http://www.daniweb.com/forums/thread197527.html
Use correct loop conditions and always test every input operation result.
For example:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
...
vector<string> v;
...
for (i = 0; getline(is,t); i++) { // you have the next record!
  Tokenize(t,v,',');
  if (v.size() >= number_of_fields) {
      // get selected fields values
  }
}
...
vector<string> v;
...
for (i = 0; getline(is,t); i++) { // you have the next record!
  Tokenize(t,v,',');
  if (v.size() >= number_of_fields) {
      // get selected fields values
  }
}

I agree with Salem: as usually, more efficient means bla-bla-bla - it's an unclear ambiguous term until you define an efficiency criterion.

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Join Date: Jul 2008

Posts: 2,001

Reputation: ArkM has much to be proud of

Solved Threads: 343

ArkM

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Postaholic

Re: More Efficient way? Grabbing numbers

Jun 16th, 2009

And yet another question to OP:
Why you are starting a new thread on the same problem?
Orphaned thread:
http://www.daniweb.com/forums/thread197527.html