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! Least-squares solver: functional interface
program example_lstsq1
use stdlib_linalg_constants, only: dp
use stdlib_linalg, only: lstsq
implicit none
integer, allocatable :: x(:),y(:)
real(dp), allocatable :: A(:,:),b(:),coef(:)
! Data set
x = [1, 2, 2]
y = [5, 13, 25]
! Fit three points using a parabola, least squares method
! A = [1 x x**2]
A = reshape([[1,1,1],x,x**2],[3,3])
b = y
! Get coefficients of y = coef(1) + x*coef(2) + x^2*coef(3)
coef = lstsq(A,b)
print *, 'parabola: ',coef
! parabola: -0.42857142857141695 1.1428571428571503 4.2857142857142811
end program example_lstsq1
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