Trying to make a vector of structures, need help

CT++ · #1 10-May-2005, 12:40

Hello,

I am writing a program that runs a bunch of statistical tests on data that is read in from a file. What I am having trouble with is storing the data in structures.

There is a data file that has rows of scores.
Right now, the program reads in each row as a string, splits the strings up, and converts each value to a float. Each float is stored as a value in a vector.

So a string like:
"11 1 1 111 111 1"

Becomes a vector with 6 elements, each one holding a float.

What I ideally want is to have something like this.

DATASET
-GROUPS
-SCORES

CPP / C++ / C Code:

struct Group
{
	vector<float> scores;	//	all scores in group
	int n;					//	number of elements in group
	int k;					//	number of groups in DATASET 
	float mean;				//	group mean
	float sumX;				//	sum of all scores in group
	float sumX_SQRD;		//	(sum of all scores) squared
	float sum_XSQRD;		//	sum of all (scores squared)
};

struct Data
{
	vector<string> allRows;
	vector<Group> groups;
	int k;					// Number of groups in dataset
	int n;					// Number of all elements in all groups
	int dfW;				// Degrees of Freedom WITHIN groups
	int dfB;				// Degrees of Freedom BETWEEN groups
	float fComp, fCrit, cF, ssBetween, ssWithin, ssTotal, msBetween, msWithin;
};

This is the code that I have working for the string conversion to a float of vectors:

CPP / C++ / C Code:

void StripNums(Data data)
//  Does a bunch of crap
{
	Header("Strip Nums");
	string temp;
	vector<Group> newvect(data.k);		// makes a vector of groups to store temp data in
	
	for (int i=0; i < data.k; i++)						//	For every row of data in the dataset
	{													//
		cout << "Row " << i+1 << ": ";					//
		while (data.allRows[i].empty()!=true)			//	Until the string for this row is empty...
	   {												//
			temp.clear();									//	Clear the temp string
			int marker = 0;									//	Set marker to zero 
			marker= data.allRows[i].find(' ');				//	Set marker to the location of first blank char in the string
			if (marker < 1)									//	If there is no whitespace...
				marker=data.allRows[i].size();				//	...set marker to the end of the string
			temp = data.allRows[i].substr(0,marker);		//	Set temp string to all chars between the start of the string and the marker
			data.allRows[i].erase(0, temp.size()+1);		//	Wipe the chars that were copied from the string, as well as the leading blank char
			float moose = atof(temp.c_str());				//	Convert the snipped string into a float
			newvect[i].scores.push_back(moose);				//	Append float to vector
		}													//
		PrintGroup(newvect[i].scores);						//	Printout scores
		cout << endl;										//
	}
}

What I cannot figure out is how to assign the values from the newvect vector into a vector that is a member of a group structure, that is part of a vector of group structures, in the dataset structure.

I thought that I could do it like this:

CPP / C++ / C Code:

	for (int xx=0; xx < data.k; xx++)
	{
		Group data.groups[xx];
		data.groups[xx] = NewGroup();
		cout << data.groups[xx].n;
	}

..but that gives me an error saying "expected initializer before '.' token", which I don't understand. I had thought that it would step through the data.groups vector of group structures, and pass each one into the fuction I wrote that assigns values to the vector of floats, but it doesn't. I think maybe I am not initializing something right, but I don't know what

Any help would be sincerely appreciated!!

CT++ · #2 10-May-2005, 12:52

For reference, this is the function I wrote that passes values into the vector of floats of a group structure:

CPP / C++ / C Code:

Group NewGroup()
{
	Group temp;
	for (int i=0; i < 5; i++)
	{
		temp.scores.push_back(1);			//	all scores in group
	}
	return temp;
}

The iteration of five and value of one are arbitray, I was just using it for testing. This function works great if I run it like this:

CPP / C++ / C Code:

Group cow;
cow = NewGroup();

I will get a cow structure that gets the value of 1 assigned to vector elements 0 through 5.

What I cannot do is get it to "fill" a structure that is part of a vector of structures.

i.e.

CPP / C++ / C Code:

vector<Group> yourmomma;
yourmomma[0] = NewGroup();
cout << yourmomma[0].scores[0];

It will compile and run, but the code above doesn't execute, and I get an "exited due to signal 10 (SIGBUS)" error.

Sokar · #3 10-May-2005, 13:36

Quote:

Originally Posted by CT++

What I cannot do is get it to "fill" a structure that is part of a vector of structures.

i.e.

CPP / C++ / C Code:

vector<Group> yourmomma;
yourmomma[0] = NewGroup();
cout << yourmomma[0].scores[0];

It will compile and run, but the code above doesn't execute, and I get an "exited due to signal 10 (SIGBUS)" error.

This is a empty vector

CPP / C++ / C Code:

vector<Group> yourmomma;

No elements you must use push_back to add to that vector.
Maybe this,

CPP / C++ / C Code:

yourmomma.push_back(NewGroup());

or
If you have an idea of how many you need you could include that when make the vector.

CPP / C++ / C Code:

vector<Group> yourmomma(20);

That will have 20 element to start with.
Now you could do something like this for 20,

CPP / C++ / C Code:

yourmomma[0] = NewGroup();

CT++ · #4 10-May-2005, 14:11

Thank you!!!!

I realized I wasn't initializing the groups properly, and ended up doing this:

CPP / C++ / C Code:

void StripNums(Data data)
//  Does a bunch of crap
{
	Header("Strip Nums");								//	Label
	string tempStr;										//	Holds value snipped from beginning of string
	Group tempGrp;										//	Temp value to initialize group structures
	for (int i=0; i < data.k; i++)						//	For each row of data in dataset
	{													//
		data.groups.push_back(tempGrp);					//	Create a group structure to hold scores & other values
	}													//
	for (int i=0; i < data.groups.size(); i++)			//	For each group just created
	{													//
		cout << "Row " << i+1 << ": ";					//	Label
		while (data.allRows[i].empty()!=true)			//	Until the string for this row is empty...
	   {												//
			tempStr.clear();								//	Set temp string to null
			int marker = 0;									//	Set marker to zero 
			marker= data.allRows[i].find(' ');				//	Set marker to location of the first blank char in this string
			if (marker < 1)									//	If there is no whitespace...
				marker=data.allRows[i].size();				//	...set marker to the end of this string
			tempStr = data.allRows[i].substr(0,marker);		//	Set temp string to all chars between the start of the string and the marker
			data.allRows[i].erase(0, tempStr.size()+1);		//	Wipe the chars that were copied from the string, as well as the leading blank char
			float moose = atof(tempStr.c_str());			//	Convert the snipped string into a float
			data.groups[i].scores.push_back(moose);			//	Append float to vector
		}													//
		PrintGroup(data.groups[i].scores);					//	Printout scores by passing vector to function
	}
}

The relevant part being:

CPP / C++ / C Code:

Group tempGrp;										//	Temp value to initialize group structures
	for (int i=0; i < data.k; i++)						//	For each row of data in dataset
	{													//
		data.groups.push_back(tempGrp);					//	Create a group structure to hold scores & other values
	}													//

I was totally flummoxed on using push_back to add a group, without having any values in it.

Thank you again

Sokar · #5 10-May-2005, 17:00

Quote:

Originally Posted by CT++

Thank you again

You are welcome.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Rate This Thread
Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Photoshop Tutorial: Make An Inspirational/Mystical Picture	ToddSAFM	Graphics Forum	9	09-Aug-2005 21:32
Delete and diplaying probrlem with structures.	glulu76	C++ Forum	2	09-May-2005 18:23