Read text array to array

[vadkortefa]

Hello, I am new to C++. I have a text file that looks like this:


(a couple lines of words)
x = [1
1 1];
o = [0 0 0];
q = [[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]];
alpha = [[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]];
beta = [[0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0]
[0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0]];
z = [[0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0]
[0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0]
[0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0]];
u = [[[0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
[[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]];


I would like to read this file into separate arrays, like the ones in the file.

Any help would be much appreciated.

[Rechard3]

well, this looks like a homework for me....
anyway, i will give you a function to read an array into its argument.
the rest is up to you.

#define X 5     //these are the dimensions of the array that will
#define Y 3     //hold the values.
#define Z 20
void ExtractArray( int a[X][Y][Z], ifstream& in);

//your code here


/*	pre-condition:	(a) is pointing to an enough allocated memory.
			(in) is connected to the input file.
 	post-condition: (a) contains the extracted array.   */
void ExtractArray( int a[X][Y][Z], ifstream& in)
{

	for(int x = 0 ; x < X ; x++)
	{
		for(int y = 0 ; y < Y ; y++)
		{
			for(int z = 0 ; z < Z ; z++)
			{
				while(in.peek() < '0' || in.peek() > '9')
				{
					in.ignore();	//ignore everything other than a digit.
				}

				a[x][y][z] = in.get() - '0';	//extract the digit, and transform
								//it from ascii to value.
			}
		}
	}
}

i think this should be enough for you to complete this journey.

[vadkortefa]

Thank you very much, this was very helpful!

(This is not a homework question.)

I have one more question. Those lines with words contain performance measures (like solve time, error bound), so they also contain numbers. So to set to pointer to where I want I'm doing this, because I know there are 14 lines before "x=":

char semmi[256];
	for(int i=0; i<14;i++){
		file.getline (semmi,256);
        }

I was wondering if there was a better way to do it. To actually find the position of "x=", in case the number of lines change.

Thank you!

[Rechard3]

i would try to ignore those lines instead of extracting them.

unsigned int nLine = 0;   //hold the number of lines passed.
do
{
    if(file.peek() == '\n')   //if reach a newline, increase nLine by 1.
    {
        nLine ++ ;
    }
    file.ignore();
}
while( (nLine < 14) && ( !file.eof() ) );  //keep iterating until passed 14 lines or reach eof. 

[vadkortefa]

Thank you very much for your help!

[vadkortefa]

I have one more question. Now I am trying to read in the data file (the previous file was the output). The data file looks like this:

T=20;
R=3;
B=3;
P=5;
K=3;
S=[15,15,15];
cf=20;
cv=2;
n=2;
d=[5,10,8,7,8];
...


My question is, how can I read in the double digit numbers.

Thank you!

[Dy7SLyTq]

are you asking how to read in just the doubles? write a mini parser type thing

[vadkortefa]

Yes. For the singe digits, I'm using the following modification of the code above:

int ExtractArraySmall2( int room, ifstream& in)
{
	   while(in.peek() < '0' || in.peek() > '9')
				{
					in.ignore();	//ignore everything other than a digit.
				}

				room = in.get() - '0';	//extract the digit, and transform
								//it from ascii to value.
				
				return room;
}

This takes one digit at a time, so I don't know how to read the double digit numbers in.

While I was working on this, I came across another problem. The X, Y, Z numbers that are defined at the beginning are things that I would like to read in from the data file (X=P, Y=R, Z=T), but when I do that this error comes up: expression must have a constant value; because these are the sizes of the arrays. Is there any way to go around that?

Thank you!

[Dy7SLyTq]

vectors

[vadkortefa]

I'm sorry, could you be more specific? As I said in the beginning of my first post, I am new to C++.

And what about reading the double digits?

Thank you!

[Rechard3]

i would try implement this algorithm:

int number = 0;
while(in.peek()>='0' && in.peek() <= '9')
{
    char temp = in.get(); // extract one byte of the number.
    temp -= '0';  // convert it from ASCII value to binary value.
    number |= temp;  // paste the extracted byte on the low order byte of number.
    number <<= temp;  //shift number 8 bits left to clear space for the next byte.
}
number >>= 8;  //  after the loop breaks, number is shifted 8bits
//left more than needed, so correct that.  

after the algorithm finishes, number will contain one number of the source stream.

EDIT - PS:
this algorithm shall be changed to be used with different encodings, like little indian.
also, if the file already contains the number as a binary value, you would delete line 5.

[vadkortefa]

Thank you very much, but it did not give the right number (which is 20). Using the following checkpoints it gave me this

while(in.peek()>='0' && in.peek() <= '9')
	{
	    char temp = in.get(); // extract one byte of the number.
	    temp -= '0';  // convert it from ASCII value to binary value.
	    number |= temp;  // paste the extracted byte on the low order byte of number.
		cout<<number<<" one\n";
	    number <<= temp;  //shift number 8 bits left to clear space for the next byte.
		cout<<number<<" two\n";
	}
	cout<<number<<" three\n";
	number >>= 8;   //  after the loop breaks, number is shifted 8bits
					//left more than needed, so correct that.  
	cout<<number<<" four\n";

Output:
2 one
8 two
8 one
8 two
8 three
0 four


The file is ANSI encoded.