Using TikZ along with picture environment

Question

Please see my examples:

• picture After TikZ

     \documentclass{article}
     \usepackage{color}
     \usepackage{tikz}
     \usepackage[english]{babel}
     \begin{document}
     \begin{tikzpicture}
     \path (0pt,0pt);% for adjusting to origin of entire document
     \draw[red]
     (0pt, 50pt) -- (120pt, 140pt) -- (240pt, 50pt);
     \end{tikzpicture}
     \begin{picture}(0,0)
     \color{blue}\qbezier(0, 50) (120, 140)(240, 50)
     \end{picture}
     \end{document}
  

Result:

• picture Before TikZ

      \documentclass{article}
      \usepackage{color}
      \usepackage{tikz}
      \usepackage[english]{babel}
      \begin{document}
      \begin{picture}(0,0)
      \color{blue}\qbezier(0, 50) (100, 140)(200, 50)
      \end{picture}
      \begin{tikzpicture}
      \path (0pt,0pt);% for adjusting to origin of entire document
      \draw[red]
      (0pt, 50pt) -- (100pt, 140pt) -- (200pt, 50pt);
      \end{tikzpicture}
      \end{document}
  

Result:

• picture Without TikZ

      \documentclass{article}
      \usepackage{color}
      \usepackage{tikz}
      \usepackage[english]{babel}
      \begin{document}
      \begin{picture}(0,0)
      \color{blue}\qbezier(0, 50) (100, 140)(200, 50)
      \end{picture}
      \end{document}
  

Result:

As you can see from 3rd example picture environment's coordinates differ from TikZ environment's coordinates. Is that possible to depict TikZ figures in the same coordinate system as picture environment has?

Answer 1

No there is no problem with coordinates. The problem is tikz uses a bounding box by default and with \begin{picture}(0,0)you don't have a bounding box with environment picture. In the first part, I use "picture" inside a tikz code and I use a bounding box for picture in other parts. Remark : you have blank spaces misplaced in your code.

\documentclass{article}
\usepackage{color}
\usepackage{tikz}
\usepackage[english]{babel}
\begin{document} 
  \parindent=0pt
\begin{tikzpicture}
   \draw[help lines,step=10pt](0,0) grid (200pt,150pt);
   %\path (0pt,0pt);
    \draw[red]  (0pt, 50pt) -- (100pt, 140pt) -- (200pt, 50pt);
    \node[inner sep=0pt,anchor=south west] at (0,0){% 
    \begin{picture}(200,140)%
       \put(0,0){\line(1,0){200}} 
        \color{blue}\qbezier(0, 50) (100, 140)(200, 50)%
    \end{picture}% 
    };     
 \end{tikzpicture}%
   \begin{picture}(200,140)% 
     \put(0,0){\line(1,0){200}}
    \color{blue}\qbezier(0, 50) (100, 140)(200, 50)%
    \end{picture}           
  \begin{picture}(0,0)
    \color{blue}\qbezier(0, 50) (100, 140)(200, 50)%
    \end{picture}% 
    \begin{tikzpicture}
    \path (0pt,0pt);
    \draw[red]
    (0pt, 50pt) -- (100pt, 140pt) -- (200pt, 50pt);
    \end{tikzpicture}        
    \end{document}

update

version with a bounding box null for the tikzpicture

\documentclass{article}
\usepackage{color}
\usepackage{tikz}  
\begin{document} 
  \parindent=0pt

\null\vspace{2cm} 

  \begin{picture}(0,0)
    \color{blue}\qbezier(0, 50) (100, 140)(200, 50)%
    \end{picture}% 
    \begin{tikzpicture}
    \draw[use as bounding box] (0,0) rectangle (0,0);     
    \path (0pt,0pt);
    \draw[red]
    (0pt, 50pt) -- (100pt, 140pt) -- (200pt, 50pt);
    \end{tikzpicture}% 
    \begin{picture}(0,0)
    \color{green}\qbezier(0, 50) (100, -90)(200, 50)%
    \end{picture}%         
\end{document} 

version with overlay

 \documentclass{article}
 \usepackage{color}
 \usepackage{tikz}  
 \begin{document} 
   \parindent=0pt

   \null\vspace{2cm} 

 \begin{picture}(0,0)
   \color{blue}\qbezier(0, 50) (100, 140)(200, 50)%
 \end{picture}% 
 \begin{tikzpicture}[overlay]
   \path (0pt,0pt);
   \draw[red]  (0pt, 50pt) -- (100pt, 140pt) -- (200pt, 50pt);
 \end{tikzpicture}% 
 \begin{picture}(0,0)
   \color{green}\qbezier(0, 50) (100, -90)(200, 50)%
 \end{picture}%          
 \end{document}

The result is the same with the two codes.