How to I realize a dot (here just drawn as a circle) which stays the same size no matter how I scale the image.
Here is the example.
\begin{tikzpicture}[scale=1]
\draw[thick] (0,0)--(1,0);
\fill (0,0) circle (1pt);
\end{tikzpicture}
\begin{tikzpicture}[scale=3]
\draw[thick] (0,0)--(1,0);
\fill (0,0) circle (1pt);
\end{tikzpicture}
Probably I should use node instead of drawing another circle.
I used to use a node with ${\bullet}$ but this is not precisely centered and I cannot control the size.
edit The following works partially, but not for a not centered point:
\begin{tikzpicture}[scale=1]
\draw[thick] (0,0)--(1,0);
\fill[shift only] (0,0) circle (1pt);
\fill[shift only] (1,0) circle (1pt);
\end{tikzpicture}
\begin{tikzpicture}[scale=3]
\draw[thick] (0,0)--(1,0);
\fill[shift only] (0,0) circle (1pt);
\fill[shift only] (1,0) circle (1pt);
\end{tikzpicture}
\begin{tikzpicture}[scale=3]
\draw[thick] (0,0)--(1,0);
\fill[shift only] (0,0) circle (1pt);
\fill(1,0) {[shift only] circle (1pt)};
\end{tikzpicture}
Alternatively, how to draw a dot at a specific point having a fixed size w.r.t. to the line thickness, e.g. 1.5x as thick as a thick
line.