How do I draw this curve on TIKZ?

Question

I need this picture with more quality for a paper but I am not as skilled on Tikz as I would like to.

I did part of the way on constructing the circles, points and arrows but, as I imagined, I can't do the details like the circle being part erased on one of the nodes. Or the strange curves with arrows T_T.

The class of the document I am using its a variation of the article class.

This is what I did so far:

\documentclass{article}
%Packages for the TIKZ%
\usepackage{xcolor}
\definecolor{azul}{RGB}{187,233,255}
\usepackage{tikz}
\usetikzlibrary{arrows,positioning} 
\tikzset{
    %Define standard arrow tip
    >=stealth',
    % Define arrow style
    pil/.style={
           ->,
           thick,
           shorten <=2pt,
           shorten >=2pt,}
}
\begin{document}
\begin{tikzpicture}
\draw[thick,->] (0,0) -- (5,0) node[anchor=north west] {x};
\draw[thick,->] (0,0) -- (0,5) node[anchor=south east] {y};
\filldraw[azul, draw=black, thick] (2.5,2.5) circle (2cm);
\filldraw[white, draw=black, thick] (2.5,2.5) circle (0.75cm);
\filldraw[black] (2.5,2.5) circle (3pt) node [anchor= south] {$\delta$};
\filldraw[black] (2.11,2.05) circle (3pt);
\draw[thick,->] (2.5,2.5) -- (3.03,3.03);
\draw[thick] (2.5,2.5) -- (1.8,3.07) node [anchor= south east] {$\epsilon$};
\draw[thick,->] (1.3,3.50) -- (0.93,3.78);
\end{tikzpicture}
\end{document}

And I get this:

The image I am trying to recreate is this:

I think your question is good, but your title is really really bad. This site is not for others to do your work, so you need a title that somehow relates to the problem you are having. (also make your code compilable by adding \documentclass, ... ) — hpekristiansen, Sep 18 '20 at 18:31

score 1 · Accepted Answer · answered Sep 18 '20 at 20:11

For a starting point and using this nice answer from Henri Menke and only for left image. The coordinates must be set manually according to your desired curve shape.

\documentclass[margin=3mm]{standalone}
%Packages for the TIKZ%
\usepackage{xcolor}
\definecolor{azul}{RGB}{187,233,255}
\usepackage{tikz}
\usetikzlibrary{arrows,positioning} 
\usetikzlibrary{decorations.markings}
\tikzset{
    %Define standard arrow tip
    >=stealth',
    % Define arrow style
    pil/.style={
           ->,
           thick,
           shorten <=2pt,
           shorten >=2pt,}
}
\tikzset{
    set arrow inside/.code={\pgfqkeys{/tikz/arrow inside}{#1}},
    set arrow inside={end/.initial=>, opt/.initial=},
    /pgf/decoration/Mark/.style={
        mark/.expanded=at position #1 with
        {
            \noexpand\arrow[\pgfkeysvalueof{/tikz/arrow inside/opt}]{\pgfkeysvalueof{/tikz/arrow inside/end}}
        }
    },
    arrow inside/.style 2 args={
        set arrow inside={#1},
        postaction={
            decorate,decoration={
                markings,Mark/.list={#2}
            }
        }
    },
}
\begin{document}
\begin{tikzpicture}
\coordinate (A) at (2.11,2.05);
\coordinate (B) at (2.5,2.5);
\draw[thick,->] (0,0) -- (5,0) node[anchor=north west] {x};
\draw[thick,->] (0,0) -- (0,5) node[anchor=south east] {y};
\filldraw[azul, draw=black, thick] (2.5,2.5) circle (2cm);
\filldraw[white, draw=black, thick] (2.5,2.5) circle (0.75cm);
\draw[thick,->] (2.5,2.5) -- (3.03,3.03);
\draw[thick] (2.5,2.5) -- (1.8,3.07) node [anchor= south east] {$\epsilon$};
\draw[thick,->] (1.3,3.50) -- (0.93,3.78);
\draw[blue,  thick] plot [smooth,tension=1]
        coordinates {(A) (2.3,2.1) (2.65,1.6) (3.5,1.8) (4,2.5)  (B)}
        [arrow inside={end=stealth,opt={blue,scale=2}}{0.3,0.5,0.75,0.97}];
\filldraw[black] (B) circle (3pt) node [anchor= south] {$\delta$};
\filldraw[black] (A) circle (3pt);
\end{tikzpicture}
\end{document}

score 1 · Answer 2 · answered Sep 19 '20 at 11:12

The two curves seem to be TikZ different; I drew the first as a hobby curve and the second as an ellipse. The markings are also different; hence I defined two types of decorations (with different types of arguments) in the preamble.

The bullet for the second curve is constructed by trial and error. Maybe, in case you need the drawing later and need to slightly modify it, it would be better to define the bullet through a parameter along the ellipse.

\documentclass[11pt, margin=1cm]{standalone}
\usepackage{tikz}
\definecolor{azul}{RGB}{187, 233, 255}
\usetikzlibrary{arrows}
\usetikzlibrary{calc, math, hobby, decorations.markings}
\tikzset{
  >=stealth',  % define standard arrow tip
  pil/.style={  % define arrow style
    ->,
    thick,
    shorten <=2pt,
    shorten >=2pt
  },
  show two/.style={%  define markings along path
    decorate, decoration={markings,
      mark=between positions .1 and .99 step .5 with {
        {\arrow[blue, line width=.8pt]{#1}};
      }
    }
  },
  show three/.style={%  define markings along path
    decorate, decoration={markings,
      mark=between positions .3 and .99 step #1 with {
        {\arrow[blue, line width=.8pt]{>}};
      }
    }
  }
}
\begin{document}
\tikzmath{
  real \R, \r;
  \R = 2;
  \r = .75;
}
\begin{tikzpicture}[every node/.style={color=black, scale=.7}]
  \draw[very thin, ->] (0,0) -- (5,0) node[anchor=north west] {$x$};
  \draw[very thin, ->] (0,0) -- (0,5) node[anchor=south east] {$y$};
\path (2.5, 2.5) coordinate (B);
  \path
  ($(B)+(240:.7\r)$) coordinate (A1)
  ($(B)+(270:.65\r)$) coordinate (A2)
  ($(B)+(269:1.3\r)$) coordinate (A3)
  ($(B)+(-70:1.8\r)$) coordinate (A4)
  ($(B)+(-25:2.2\r)$) coordinate (A5)
  ($(B)+(15:2.\r)$) coordinate (A6)
  ($(B)+(-10:.9\r)$) coordinate (A7)
  ($(B)+(-30:.8\r)$) coordinate (A8);
\draw[fill=azul, even odd rule] (B) circle (\R) (B) circle (\r);
  \draw[->, gray] (B) -- node[pos=.6, fill=azul] {$\epsilon$} +(135: \R);
  \draw[->, gray] (B) -- node[anchor=west, inner sep=1pt] {$\delta$} +(85: \r);
\draw[blue, thick, postaction={show three={.28}}]
  (A1) to[curve through={(A2) (A3) (A4) (A5) (A6) (A7) (A8)}] (B);
  \filldraw (B) circle (1.5pt) (A1) circle (1.5pt)
  node[anchor=north east, inner sep=1pt] {$(\phi(0),\psi(0))$}; 
\end{tikzpicture}
\begin{tikzpicture}[every node/.style={color=black, scale=.7}]
  \draw[very thin, ->] (0,0) -- (5,0) node[anchor=north west] {$x$};
  \draw[very thin, ->] (0,0) -- (0,5) node[anchor=south east] {$y$};
\path (2.5, 2.5) coordinate (B);
  \path ($(B)+(155:.76*\r)$) coordinate (A1);
\draw[fill=azul, even odd rule] (B) circle (\R) (B) circle (\r);
  \draw[->, gray] (B) -- node[pos=.6, fill=azul] {$\epsilon$} +(130: \R);
  \draw[->, gray] (B)
  -- node[pos=.4, anchor=south east, inner sep=1pt] {$\delta$} +(55: \r);
\draw[blue, thick, postaction={show two={<}}, rotate=35]
  (B) ellipse[x radius={\R-.01}, y radius=.5];
  \filldraw (B) circle (1.5pt) (A1) circle (1.5pt)
  node[anchor=south east, inner sep=1pt] {$(\phi(0),\psi(0))$};
\end{tikzpicture}
\end{document}

How do I draw this curve on TIKZ?

2 Answers2