Thread: Reading Floats from a File

how you are filling your array for one,

Code:

        double data[300];
        int Fsize = 0;
        while(!feof(fpin))
        { 
             // fills an array type double
             fscanf(fpin, "%lf", &data[Fsize]);
             Fsize++; // get actual count of size used as well
        }

if you didn't you're going to want 'a ::: check your min start value as well.

My curiosity is up now. How did you get to opening files and reading them, before you had been given exposure on arrays?
in other words,
How to loop arrays to get values in and out of them?

COMMENTS INSIDE OF CODE

Code:

#include <stdio.h>
#include <stdlib.h>


// NOT NEEDED 
// YOU'RE NOT USING ANY MATH FUNCTIONS
//JUST DOING BASIC MATH WITHOUT FUNCTIONS TO 
//DO THEM FOR YOU

//#include <math.h>


/*** MY TEST FILE IS THIS 
3.900000
3.700000
4.200000
1.000000
6.100000
9.700000
* 
*  total 28.6 / 6 = adv 4.7666 rounded 4.77
* 
* ****/

#define MAX_SZ 300
int main()
{
    int data[MAX_SZ];   // ARRAY TYPE INT you're using double
    int Fsize = 0;
    int  i=0;    //array of data
    double data_in, min=0.0, max=0.0;     //max and min of data set
    double sum = 0.0, avg;     //average, standard deviation, range of data set
    
      
    
// YOUR CODE
// NO ARRAY BEING FILLED
// the only thing inside of your array is crap memory/data values
// given to it by the computer it is running on. 

    FILE *fpin;
    fpin = fopen("data.txt","r");

    for(i=0;i<199;i++)
    {
        fscanf(fpin, "%lf", &data_in); // NO ARRAY BEING FILLED
       if (data[i]>max) // NO ARRAY VALUES TO READ
       {
           max = data[i]; // NO ARRAY VALUES TO ASSIGN
       }
       if (data[i]<min) // NO ARRAY VALUES TO READ
       {
           min = data[i]; // NO ARRAY VALUES TO ASSIGN
       }
    }
        for(i=0;i<199;i++)
        {
           fscanf(fpin, "%lf", &data_in);
           sum += data[i]; // NO ARRAY VALUES TO ADD UP
           avg = sum / 200.0; // NO REAL RESULTS 
        }
    printf("\n\n scotdani code\n\n");
    printf("The sum value of this data set is %.02lf.\n\n", sum);
    printf("The minimum value of this data set is %lf.\n", min);
    printf("The maximum value of this data set is %lf.\n", max);
    printf("The average value of this data set is %lf.\n", avg);
    printf("----------------------------------------------------\n");
    printf("----------------------------------------------------\n");
    printf("\n");


    
    
// OPERATION ONE

// DOES COMPUTATIONS AND FILLS ARRAY AT SAME TIME

// PROPER DATA TYPE ARRAY OF DOUBLE
    double data1[MAX_SZ] = { 0.0 };
 
    // reset everything

    fseek(fpin, 0, SEEK_SET);
    

// SET MIN TO GREATER THAN 0.0 THAT IS THE LOWEST 
//IT WILL PRODUCE FALSE READING IF DATA IN FILE IS GREATER THAN 0.0
//NOTHING IN FILE CAN GET LOWER THAN 0.0 UNLESS IT IS -NEG THEN
//THAT IS NEGATIVE ISN'T IT. -1.0, 0.0, 0.1

    sum = 0.0 , min=9999999990.0, max=0.0, avg = 0.0, data_in = 0.0; // reset values
    Fsize = 0;

    
    
    // makes array obsolete because everything 
    // is being done while reading
    //the data and storing it into the array.
    // this only makes the
    // array useful if user needs it
    // for later on. 

    while(!feof(fpin)) // seeks for end of file when found loops stops. 
    {
        fscanf(fpin, "%lf", &data1[Fsize]);
        
        if (data1[Fsize]>max)
        {
            max = data1[Fsize];
        }
        if (data1[Fsize]<min)
        {
            min = data1[Fsize];
        }
        sum += data1[Fsize];
            
            Fsize++; // moves the array elements by value inside of it
    }
    //avg = sum / 200.0;
    avg = sum / 6.0;
    
  
       
    printf("The sum value of this data1 set is %.02lf.\n\n", sum);
    printf("The minimum value of this data1 set is %.02lf.\n", min);
    printf("The maximum value of this data1 set is %.02lf.\n", max);
    printf("The average value of this data1 set is %.02lf.\n", avg);    
    printf("----------------------------------------------------\n");
    printf("\n");
    

// OPERATION TWO

// DOES COMPUTATIONS WITHOUT USE OF AN ARRAY

    //reset everything
     fseek(fpin, 0, SEEK_SET);
   
   
    sum = 0.0 , min=9999999990.0, max=0.0, avg = 0.0, data_in = 0.0;
    Fsize = 0;
    // here the same thing 
    // is taking place
    // without storing
    // data into a contaner typed 
    // as an array
    for(i=0;i<6;i++)
    {
        fscanf(fpin, "%lf", &data_in);
        
        if (data_in>max)
        {
            max = data_in;
        }
        if (data_in<min)
        {
            min = data_in;
        }
        sum += data_in;     
    }
    //avg = sum / 200.0;
    avg = sum / 6.0;
    
    printf("The sum value of this data1 set is %.02lf.\n\n", sum);
    printf("The minimum value of this data1 set is %.02lf.\n", min);
    printf("The maximum value of this data1 set is %.02lf.\n", max);
    printf("The average value of this data1 set is %.02lf.\n", avg);
    printf("----------------------------------------------------\n");
       printf("\n");
 



// OPERATION THREE

// FILLS ARRAY THEN DOES THE COMPUTATIONS ON DATA WITHIN SAME ARRAY

    // reset everything
    fseek(fpin, 0, SEEK_SET);
  
    for ( int i = 0; i<MAX_SZ; i++) data1[i] = 0.0;
    sum = 0.0 , min=9999999990.0, max=0.0, avg = 0.0, data_in = 0.0; 
    Fsize = 0;
    
    while(!feof(fpin))
    { 
        // fills an array type double
        fscanf(fpin, "%lf", &data1[Fsize]);
        Fsize++; // get actual count of size used as well
    }
    for ( i = 0; i < Fsize; i++)
    {
        if (data1[i]>max)
        {
            max = data1[i];
        }
        if (data1[i]<min)
        { 
            min = data1[i];
        }
        sum += data1[i];
    }
    //avg = sum / 200.0;
    avg = sum / 6.0;
    
    printf("The sum value of this data1 set is %.02lf.\n\n", sum);
    printf("The minimum value of this data1 set is %.02lf.\n", min);
    printf("The maximum value of this data1 set is %.02lf.\n", max);
    printf("The average value of this data1 set is %.02lf.\n", avg);
    printf("\n");
    fclose(fpin); // Close File after Reading
    
    return 0;
}

Results

Code:

$ ./reading_floats_from_a_file


 scotdani code

The sum value of this data set is -13910352430.00.

The minimum value of this data set is -1565315752.000000.
The maximum value of this data set is 2027877040.000000.
The average value of this data set is -69551762.150000.

----------------------------------------------------
----------------------------------------------------

The sum value of this data1 set is 28.60.

The minimum value of this data1 set is 1.00.
The maximum value of this data1 set is 9.70.
The average value of this data1 set is 4.77.
----------------------------------------------------

The sum value of this data1 set is 28.60.

The minimum value of this data1 set is 1.00.
The maximum value of this data1 set is 9.70.
The average value of this data1 set is 4.77.
----------------------------------------------------

The sum value of this data1 set is 28.60.

The minimum value of this data1 set is 1.00.
The maximum value of this data1 set is 9.70.
The average value of this data1 set is 4.77.

userx@slackwhere:~/bin

just a little on array's

Code:

double array[amount of elements wanted]; // takes in double values
float array[amount of elements wanted]; // takes in float values
int array[amount of elements wanted]; // takes in int values

//to add values inside of each element one at a time.
int count; // the array's are zero based, 0 thru .... so the elements are integers.


// putting values inside of an array, amount is or can be an unknown
for (count = 0; count < amount_of_data_being_read_in; count++)
{
      array[count] = value_being_put_inside_of_it;
}


// count already holds the amount of elements used.


//to get values out of array one at a time; 
//Because size is now a known. We use count again. 
// count prevents the over shooting of the array. 

for (int  i = 0; i < count; i++)
{
    printf("Array element Number is %d \nvalue inside of array[ %d ]\n", i , array[ i ]);
}

Knowing the amount of data being read in needs to be found out ahead of time so the programmer can have a really good idea on how big to make the array. If not known then all one can do is guess. So making an array bigger then one might expect to use is not a bad idea for them just in case situations.

this is why the programmer needs at least an idea of how big will the data will be so he or she can code for that.

dynamic growth is a way to get around that

here fscanf is not even checking for eof

C library function fscanf()


this is where I got my information
How to use EOF to run through a text file in C? - Stack Overflow

Code:

Using fread():
char buffer[BUFFER_SIZE];
while (fread(buffer, sizeof buffer, 1, stream) == 1) // expecting 1 
                                                     // element of size
                                                     // BUFFER_SIZE
{
   // process buffer
}
if (feof(stream))
{
  // hit end of file
}
else
{
  // some other error interrupted read
}  
Note that the form is the same for all of them: check the result of the read operation; if it failed,
 then check for EOF.  You'll see a lot of examples like:
  while(!feof(stream))
{
  fscanf(stream, "%s", buffer);
  ...
} 
  Note that the form is the same for all of them:

that is as far as I read.

1. printf, scanf
2. if, else, while
3. for, switch, do
4. functions, scope, random, recursion
5. arrays, search, sort
6. pointers, sizeof
7. character functions, string functions
8. advanced printf, advanced scanf
9. structs, bitwise
10. file processing
11. linked lists, stacks, queues, trees
12. preprocessor directives
13. redirecting I/O, command line arguments, dynamic memory

is the order the book I learn from arranges subjects. I think it is a good order, except I would move dynamic memory in with arrays. I had to do that anyway since I can't use variable length arrays in my IDE. Binary calculations should be a part of bitwise, and base conversion (hex, oct, binary, dec) is an appendix subject.

For loops are completely foreign to me.

for loops are really just a one liner for a common loop structure.

Code:

for (int i = 0; i < 10; ++i) {
    // do something
}

is the same thing as:

Code:

int i = 0;
while (i < 10) {
    // do something
    ++i;
}

The only reasons to use for loops is either if you want to be lazy/efficient or you think for loops look nicer. I use them for these reasons, but while is easier to debug.