PRO linear_function_2_x, X, A, F, pder

	F=A[0]+X*A[1]
;	F=A[0]+X*12.5
;Use, for example, with
;
; X=findgen(10)+1
; Y=findgen(10)+20
; A=[20,1]
; weights=findgen(10)
; weights(*)=1
; yfit=curvefit(X,Y,weights,A,/noderivative,function_name='linear_function')

end