Duas linhas do tempo com tikzpicture?

Question

Estou tentando criar duas linhas do tempo com o tikzpicture. O de cima está como eu quero, mas estou tendo problemas com o de baixo. Em vez de ter pequenas marcas verticais, estou gerando grandes diagonais.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{snakes}
\usepackage{fullpage}
\usepackage{graphicx}


\begin{document}
\resizebox{\linewidth}{!}{% Resize table to fit within
\begin{tikzpicture}[snake=zigzag, line before snake = 5mm, line after snake = 5mm]
%draw horizontal line
\draw (0,0) -- (19/2,0);
\draw[snake] (19/2,0) -- (25/2,0);
\draw (25/2,0) -- (30/2,0);
\draw[snake] (30/2,0) -- (35/2,0);
\draw (35/2,0) -- (40/2,0);
%draw vertical lines
\foreach \x in {0, 5, 10, 19, 30, 40}{
   \draw (\x/2,3pt) -- (\x/2,-3pt);
}
%draw nodes
\draw (-2,0) node { PHYS1060 };

\draw (0,0) node[below=3pt] { Pre-test published } node[above=3pt] { Jan 4, 2014  };
\draw (5/2,0) node[below=3pt] { Nudge } node[above=3pt] { Jan 9, 2014  };
\draw (10/2,0) node[below=3pt] { First class } node[above=3pt] { Jan 13, 2014  };
\draw (19/2,0) node[below=3pt] { Pre-test due } node[above=3pt] { Jan 22, 2014  };
\draw (30/2,0) node[below=3pt] { Midterm } node[above=3pt] { Feb 17, 2014  };
\draw (40/2,0) node[below=3pt] { Final Exam} node[above=3pt] { May 5, 2014  };


%draw horizontal line
\draw (-2,-2) node { PHYS1050 };
\draw (0,-2) -- (19/2,-2);
\draw[snake] (19/2,-2) -- (25/2,-2);
\draw (25/2,-2) -- (30/2,-2);
\draw[snake] (30/2,-2) -- (35/2,-2);
\draw (35/2,-2) -- (40/2,-2);
draw vertical lines
\foreach \x in {0, 5, 10, 19, 30, 40}{
   \draw (\x/2,-2,3pt) -- (\x/2,-2,-3pt);
}


%draw nodes
\draw (0,-2) node[below=3pt] { Pre-test published } node[above=3pt] { Aug 10, 2014  };
\draw (5/2,-2) node[below=3pt] { First class } node[above=3pt] { Aug 27, 2014  };
\draw (10/2,-2) node[below=3pt] { Nudge } node[above=3pt] { Sept 4, 2014  };
\draw (19/2,-2) node[below=3pt] { Pre-test due } node[above=3pt] { Sept 7, 2014  };
\draw (30/2,-2) node[below=3pt] { Midterm } node[above=3pt] { ?, 2014  };
\draw (40/2,-2) node[below=3pt] { Final Exam} node[above=3pt] { ?, 2014  };

\end{tikzpicture}
}

\end{document}

O que estou fazendo de errado e como posso consertar?

Obrigado!

Answer 1

Eu definiria explicitamente as coordenadas de suas linhas verticais.

Portanto, suas primeiras linhas verticais se tornariam:

\foreach \x in {0, 5, 10, 19, 30, 40}{
   \draw (\x/2,-0.2) -- (\x/2,0.2);
}

e o segundo conjunto seria

\foreach \x in {0, 5, 10, 19, 30, 40}{
   \draw (\x/2,-2.2) -- (\x/2,-1.8);
}

Answer 2

O cálculo da coordenada y para as linhas verticais no segundo caso está errado. No primeiro caso funciona, porque a linha horizontal está na altura 0. No segundo caso você deve adicionar o offset -2, o que pode ser conseguido com a calc-library.

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{snakes}
\usepackage{fullpage}
\usepackage{graphicx}
\usetikzlibrary{calc}


\begin{document}
\resizebox{\linewidth}{!}{% Resize table to fit within
\begin{tikzpicture}[snake=zigzag, line before snake = 5mm, line after snake = 5mm]
%draw horizontal line
\draw (0,0) -- (19/2,0);
\draw[snake] (19/2,0) -- (25/2,0);
\draw (25/2,0) -- (30/2,0);
\draw[snake] (30/2,0) -- (35/2,0);
\draw (35/2,0) -- (40/2,0);
%draw vertical lines
\foreach \x in {0, 5, 10, 19, 30, 40}{
   \draw (\x/2,3pt) -- (\x/2,-3pt);
}
%draw nodes
\draw (-2,0) node { PHYS1060 };

\draw (0,0) node[below=3pt] { Pre-test published } node[above=3pt] { Jan 4, 2014  };
\draw (5/2,0) node[below=3pt] { Nudge } node[above=3pt] { Jan 9, 2014  };
\draw (10/2,0) node[below=3pt] { First class } node[above=3pt] { Jan 13, 2014  };
\draw (19/2,0) node[below=3pt] { Pre-test due } node[above=3pt] { Jan 22, 2014  };
\draw (30/2,0) node[below=3pt] { Midterm } node[above=3pt] { Feb 17, 2014  };
\draw (40/2,0) node[below=3pt] { Final Exam} node[above=3pt] { May 5, 2014  };


%draw horizontal line
\draw (-2,-2) node { PHYS1050 };
\draw (0,-2) -- (19/2,-2);
\draw[snake] (19/2,-2) -- (25/2,-2);
\draw (25/2,-2) -- (30/2,-2);
\draw[snake] (30/2,-2) -- (35/2,-2);
\draw (35/2,-2) -- (40/2,-2);
draw vertical lines
\foreach \x in {0, 5, 10, 19, 30, 40}{
   \draw ($(0,-2)+(\x/2, 3pt)$) -- ($(0,-2)+(\x/2, -3pt)$);
}


%draw nodes
\draw (0,-2) node[below=3pt] { Pre-test published } node[above=3pt] { Aug 10, 2014  };
\draw (5/2,-2) node[below=3pt] { First class } node[above=3pt] { Aug 27, 2014  };
\draw (10/2,-2) node[below=3pt] { Nudge } node[above=3pt] { Sept 4, 2014  };
\draw (19/2,-2) node[below=3pt] { Pre-test due } node[above=3pt] { Sept 7, 2014  };
\draw (30/2,-2) node[below=3pt] { Midterm } node[above=3pt] { ?, 2014  };
\draw (40/2,-2) node[below=3pt] { Final Exam} node[above=3pt] { ?, 2014  };

\end{tikzpicture}
}

\end{document}