Questions about (linear or nonlinear) least-squares, an estimation method used in statistics, signal processing and elsewhere.
Questions tagged [least-squares]
1853 questions
0
votes
1 answer
How to approach this least square projection question?
A simple linear regression model as follows,
\begin{align}
Y=\beta_0+\beta_1 X+\epsilon
\end{align}
Now I would like to replace $X$ with another variable $Z$. I only know $X$
and $Z$ are correlated but do not know the true functional form of the…
Vincent
- 139
- 5
-1
votes
2 answers
the best approximation to sgn$(x)$ in the least square sense
Find the best approximation to $f(x)$ = sgn$(x)$ by a function $f^*(x) =
\alpha_0 + \alpha_1 x + \alpha_2x^3$ on the interval $[−1, 1]$, in the least squares sense.
I know what mean sgn$(x)$ but I don't know what mean $f^*(x)$ and how to count best…
Vinci
- 9
-2
votes
1 answer
Not a good least squares fit, what is the problem, I can not fitting the Curve peak
can not fit the curve peak:click see the fig
data= {{-40,5},{-30,5},{-20,10},{-15,20},{-13,25},
{-10,27},{-7,45},{-2,70},{-1,120},{0,220},
{1,300},{2,330},{4,300},{6,270},{7,250},
…
Le jin
- 3