来自“\node”的非法度量单位

Question

我有以下 tikz 命令

        \begin{tikzpicture}
            \node at (3.2,0) {$\mathbb{R}$};
            \node at (-.2,-.25) {$I$};
            \draw (-3,0) --(3,0);

            \node at (-1.3,2) {$U$};

            \node at (2.2,1.6) {$^+U$};
            \draw plot[smooth] coordinates
                {(1,0)(2,1)(0,3)(-2,0)};

            \node at (2.2,-1.6) {$^-U$};
            \draw plot[smooth] coordinates
                {(1,0)(2,-1)(0,-3)(-2,0)};

            \node at (.3.4,1.5) {$z$};
            \node at (.3,1.5) {\textbullet};
            \draw[dashed] (.3,0) -- (.3,1.5);

            \node at (.3.4,-1.5) {$\conj{z}$};
            \node at (.3,-1.5) {\textbullet};
            \draw[dashed] (.3,0) -- (.3,-1.5);
        \end{tikzpicture}

当我尝试编译它时，控制台Illegal unit of measure (pt inserted).在以下行显示\node at (.3.4,-1.5)。其他行似乎没有问题。这里出了什么问题？

Answer 1

坐标中的第一个点是错误的……应该是

 \node at (3.4,1.5) {$z$};

或者可能

\node at (.3,1.5) {$z$};