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Jun 16th, 2009

More Efficient way? Grabbing numbers

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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.

Quote ...

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?

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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gretty

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Solved Threads: 7

Junior Poster

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158 posts
since Apr 2009

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Jun 16th, 2009

Re: More Efficient way? Grabbing numbers

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.

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.

Salem

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Posting Sage

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7,164 posts
since Dec 2005

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Jun 16th, 2009

Re: More Efficient way? Grabbing numbers

Yet another tip:

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:

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.

ArkM

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Postaholic

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2,001 posts
since Jul 2008

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Jun 16th, 2009

Re: More Efficient way? Grabbing numbers

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

ArkM

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Solved Threads: 347

Postaholic

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since Jul 2008

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

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