tikz-pgf 线性回归-从特定点开始

Question

How to start linear regression from (0,1)?
    with this resultat 

t        x
0         1
0.01634   1.2822232
0.04902   1.9517734
0.081699  2.5069444
0.163399  4.0196319
0.245098  5.4139861
0.326797  6.4559171 



\documentclass{standalone}   
 % Required package

    \usepackage{pgfplots}
    \usepackage{pgfplotstable}
    \pgfplotsset{compat = newest}
    
    \begin{document}
        
        \begin{tikzpicture}
            \begin{axis}[
                xmin = 0, xmax = 0.5,
                ymin = 0, ymax = 11,
                width = \textwidth,
                height = 0.75\textwidth,
                xtick distance = 0.1,
                ytick distance = 1,
                grid = both,
                minor tick num = 1,
                major grid style = {lightgray},
                minor grid style = {lightgray!25},
                xlabel = {Time ($t$)},
                ylabel = {Position ($x$)},
                legend cell align = {left},
                legend pos = north west
                ]
                
                % Plot data
                \addplot[
                teal, 
                only marks
                ] table[x = t, y = x] {result.dat};
                
                % Linear regression
                \addplot[
                thick,
                orange,
                ] table[
                x = t,
                y = {create col/linear regression={y=x}}
                ] {result.dat};
                
                % Add legend
                \addlegendentry{Data}
                \addlegendentry{
                    Linear regression: $ x =
                    \pgfmathprintnumber{\pgfplotstableregressiona}
                    \cdot t
                    \pgfmathprintnumber[print sign]{\pgfplotstableregressionb}$
                };
                
            \end{axis}
            
        \end{tikzpicture}
        
    \end{document}

Answer 1

抱歉，有一段时间忘记了这件事。

---

这看起来有点奇怪，但对于一次性的事情，你可以这样做

 \addplot[thick, black] coordinates {
      (0,1)
      (0.326797, \pgfplotstableregressionb + 0.326797 * \pgfplotstableregressiona)
       };

\addplot在计算回归线的位置之后。若不绘制实际的回归线，则仅使用draw=none, forget plot该图的选项。

在下面的代码中我改变了图例条目，因为你画的线实际上不是线性回归。

\documentclass{standalone}   
\usepackage{pgfplotstable}
\pgfplotsset{compat = newest}
\pgfplotstableread{
t        x
0         1
0.01634   1.2822232
0.04902   1.9517734
0.081699  2.5069444
0.163399  4.0196319
0.245098  5.4139861
0.326797  6.4559171 
}\datatable    
    \begin{document}
        
        \begin{tikzpicture}
            \begin{axis}[
                xmin = 0, xmax = 0.5,
                ymin = 0, ymax = 11,
                width = \textwidth,
                height = 0.75\textwidth,
                xtick distance = 0.1,
                ytick distance = 1,
                grid = both,
                minor tick num = 1,
                major grid style = {lightgray},
                minor grid style = {lightgray!25},
                xlabel = {Time ($t$)},
                ylabel = {Position ($x$)},
                legend cell align = {left},
                legend pos = north west
                ]
                
                % Plot data
                \addplot[
                teal, 
                only marks
                ] table[x = t, y = x] {\datatable};
                
                % Linear regression
                \addplot[
                draw=none, forget plot
                ] table[
                x = t,
                y = {create col/linear regression={y=x}}
                ] {\datatable};
 
                 \addplot[thick, black] coordinates {
                   (0,1)
                   (0.326797, \pgfplotstableregressionb + 0.326797 * \pgfplotstableregressiona)};
 
                % Add legend
                \addlegendentry{Data}
                \addlegendentry{
                    Linear fit
                };
                
            \end{axis}
            
        \end{tikzpicture}
        
    \end{document}