TikZ 中的负坐标

Question

我正在尝试使用 Tikz。不幸的是，当我使用负坐标时似乎出了问题：代码的最后一行

\begin{tikzpicture}[scale=2]
\draw [->] (-1,0) -- (3.2,0); 
\draw [->] (0,-1.125) -- (0,3.2);
\draw (-0.75 : -0.5)--(1.5,2.25);
\end{tikzpicture}

绘制一条从 (-0.75,0) 开始的线，而不是从 (-0,75,-0.5) 开始的线。这是怎么回事？

Answer 1

尝试这个

\begin{tikzpicture}[scale=2]
\draw [->] (-1,0) -- (3.2,0); 
\draw [->] (0,-1.125) -- (0,3.2);
%\draw (-0.75 : -0.5)--(1.5,2.25); % `:' gives you polar coordinate, but 
                                   % you are looking for canva coordinate
                                   % (Cartesian coordinate), so you need 
                                   % `,' in the place of `:'.
 \draw (-0.75 , -0.5)--(1.5,2.25);
\end{tikzpicture}