gnuplotの設定ファイル .gnuplot

.gnuplotrcじゃなくて.gnuplotね。

他のシステムではgnuplot.iniか

gnuplot> help startup
 When `gnuplot` is run, it looks for an initialization file to load.
 This file is called `.gnuplot` on Unix and AmigaOS systems, and
 `GNUPLOT.INI` on other systems.  If this file is not found in the
 current directory, the program will look for it in the HOME directory
 (under AmigaOS, Atari(single)TOS, MS-DOS, Windows and OS/2, the
 environment variable `GNUPLOT` should contain the name of this
 directory; on Windows NT, it will use `USERPROFILE` if GNUPLOT isn't
 defined).  Note: if NOCWDRC is defined during the installation,
 `gnuplot` will not read from the current directory.

 If the initialization file is found, `gnuplot` executes the commands in it.
 These may be any legal `gnuplot` commands, but typically they are limited to
 setting the terminal and defining frequently-used functions or variables.

ということで ~/.gnuplotに以下を記述すれば、高校数学は余裕か。
＃陰関数とかはパラメータ記述じゃないと無理そうだけど

set xzeroaxis lt -1
set yzeroaxis lt -1
set xtics 1
set ytics 1
set grid
set xrange [-10:10]
set yrange [-10:10]