Performs the linear fit of a dataset with the least squares method.
To run program under GNU/Linux simply execute bash script with: bash start.sh
Under Windows first compile stat.c library with: gcc -c stat.c -lm
After compile Least_Squares.c with: gcc Least_Squares.c stat.o -lm
Create a file with following format: x y sigma(y)
The file's lines must be equal to the number of points!
The angular coefficient is estimated with weighted averages of weights = sigma(y); do not insert experimental uncertainties equal to sigma(y) = 0