我正在使用 pgfplots 繪製圖表，我想在繪製資料時修改資料的橫座標值。我目前正在使用x filter/.code={\pgfmathparse{1/#1} \pgfmathresult}x 值的倒數。然而，對於這個數學運算來說，似乎存在著精度上的欠缺。這是 MWE，其中輸出不是想要的：
\documentclass[a4paper]{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[%
width=10cm,
height=5cm,
]
\addplot [x filter/.code={\pgfmathparse{1/#1} \pgfmathresult}]
table[row sep=crcr]{%
665.123474243553 50.0709210000000\\
665.124802332690 49.6678125000000\\
665.126130403923 49.7686245000000\\
665.127458480460 49.7501640000000\\
665.128786585510 49.6496310000000\\
665.130114672653 49.8061035000000\\
665.131442788313 50.1225825000000\\
665.132770886063 49.5357525000000\\
665.134099012330 49.4506110000000\\
665.135427120687 50.0079600000000\\
665.136755257560 49.0017465000000\\
665.138083376527 49.5523995000000\\
665.139411524010 49.7646720000000\\
665.140739653583 49.7826210000000\\
665.142067788460 49.3249215000000\\
665.143395951857 48.9346470000000\\
665.144724097340 48.6674580000000\\
665.146052271343 48.2280330000000\\
665.147380427437 46.8564690000000\\
665.148708612050 46.2079800000000\\
665.150036778750 44.7215610000000\\
665.151364973970 44.2429365000000\\
665.152693151283 43.3782690000000\\
665.154021357110 44.1923910000000\\
665.155349545030 44.8409730000000\\
665.156677761467 45.3737235000000\\
665.158005959997 46.7979255000000\\
665.159334163827 47.2520910000000\\
665.160662396177 48.7288845000000\\
665.161990610620 48.5122410000000\\
665.163318853580 49.2502890000000\\
665.164647078630 48.5547885000000\\
665.165975332200 49.2531720000000\\
665.167303567860 50.3161155000000\\
665.168631832037 49.4624685000000\\
665.169960078307 49.6258695000000\\
665.171288353093 50.0582730000000\\
665.172616609973 49.7700195000000\\
665.173944872157 49.7608590000000\\
665.175273162857 49.8229830000000\\
665.176601435650 49.8743190000000\\
665.177929736963 49.8491160000000\\
};
\end{axis}
\end{tikzpicture}
\end{document}
有沒有辦法提高精度？
編輯解決方案：
\documentclass[a4paper]{article}
\usepackage{pgfplots,xfp}
\begin{document}
\begin{tikzpicture}
\begin{axis}[%
width=10cm,
height=5cm,
xticklabel style={/pgf/number format/fixed,/pgf/number format/precision=6, rotate=45}
]
\addplot [x filter/.code={\def\pgfmathresult{\fpeval{1/#1}}}]
table[row sep=crcr]{%
665.123474243553 50.0709210000000\\
665.124802332690 49.6678125000000\\
665.126130403923 49.7686245000000\\
665.127458480460 49.7501640000000\\
665.128786585510 49.6496310000000\\
665.130114672653 49.8061035000000\\
665.131442788313 50.1225825000000\\
665.132770886063 49.5357525000000\\
665.134099012330 49.4506110000000\\
665.135427120687 50.0079600000000\\
665.136755257560 49.0017465000000\\
665.138083376527 49.5523995000000\\
665.139411524010 49.7646720000000\\
665.140739653583 49.7826210000000\\
665.142067788460 49.3249215000000\\
665.143395951857 48.9346470000000\\
665.144724097340 48.6674580000000\\
665.146052271343 48.2280330000000\\
665.147380427437 46.8564690000000\\
665.148708612050 46.2079800000000\\
665.150036778750 44.7215610000000\\
665.151364973970 44.2429365000000\\
665.152693151283 43.3782690000000\\
665.154021357110 44.1923910000000\\
665.155349545030 44.8409730000000\\
665.156677761467 45.3737235000000\\
665.158005959997 46.7979255000000\\
665.159334163827 47.2520910000000\\
665.160662396177 48.7288845000000\\
665.161990610620 48.5122410000000\\
665.163318853580 49.2502890000000\\
665.164647078630 48.5547885000000\\
665.165975332200 49.2531720000000\\
665.167303567860 50.3161155000000\\
665.168631832037 49.4624685000000\\
665.169960078307 49.6258695000000\\
665.171288353093 50.0582730000000\\
665.172616609973 49.7700195000000\\
665.173944872157 49.7608590000000\\
665.175273162857 49.8229830000000\\
665.176601435650 49.8743190000000\\
665.177929736963 49.8491160000000\\
};
\end{axis}
\end{tikzpicture}
\end{document}
答案1
使用 xfp 我得到這個
\documentclass[a4paper]{article}
\usepackage{pgfplots,xfp}
\begin{document}
\begin{tikzpicture}
\begin{axis}[%
width=10cm,
height=5cm,
]
\addplot [x filter/.code={\fpeval{1/#1}}]
table[row sep=crcr]{%
665.123474243553 50.0709210000000\\
665.124802332690 49.6678125000000\\
665.126130403923 49.7686245000000\\
665.127458480460 49.7501640000000\\
665.128786585510 49.6496310000000\\
665.130114672653 49.8061035000000\\
665.131442788313 50.1225825000000\\
665.132770886063 49.5357525000000\\
665.134099012330 49.4506110000000\\
665.135427120687 50.0079600000000\\
665.136755257560 49.0017465000000\\
665.138083376527 49.5523995000000\\
665.139411524010 49.7646720000000\\
665.140739653583 49.7826210000000\\
665.142067788460 49.3249215000000\\
665.143395951857 48.9346470000000\\
665.144724097340 48.6674580000000\\
665.146052271343 48.2280330000000\\
665.147380427437 46.8564690000000\\
665.148708612050 46.2079800000000\\
665.150036778750 44.7215610000000\\
665.151364973970 44.2429365000000\\
665.152693151283 43.3782690000000\\
665.154021357110 44.1923910000000\\
665.155349545030 44.8409730000000\\
665.156677761467 45.3737235000000\\
665.158005959997 46.7979255000000\\
665.159334163827 47.2520910000000\\
665.160662396177 48.7288845000000\\
665.161990610620 48.5122410000000\\
665.163318853580 49.2502890000000\\
665.164647078630 48.5547885000000\\
665.165975332200 49.2531720000000\\
665.167303567860 50.3161155000000\\
665.168631832037 49.4624685000000\\
665.169960078307 49.6258695000000\\
665.171288353093 50.0582730000000\\
665.172616609973 49.7700195000000\\
665.173944872157 49.7608590000000\\
665.175273162857 49.8229830000000\\
665.176601435650 49.8743190000000\\
665.177929736963 49.8491160000000\\
};
\end{axis}
\end{tikzpicture}
\end{document}