1.2 Introduction

`gnuplot` is a command-driven interactive function and data plotting program.

Any command-line arguments are assumed to be names of files containing `gnuplot` commands, with the exception of standard X11 arguments, which are processed first. Each file is loaded with the `load` command, in the order specified. `gnuplot` exits after the last file is processed. The special filename "-" is used to denote standard input. When no load files are named, `gnuplot` enters into an interactive mode. See help for `batch/interactive` for more details.

`gnuplot` is case sensitive (commands and function names written in lowercase are not the same as those written in CAPS). All command names may be abbreviated as long as the abbreviation is not ambiguous. Any number of commands may appear on a line (with the exception that `load` or call must be the final command), separated by semicolons (;). Strings are indicated with quotes. They may be either single or double quotation marks, e.g.,

      load "filename"
      cd 'dir'

although there are some subtle differences (see `syntax` for more details).

Many `gnuplot` commands have multiple options. Version 4 is less sensitive to the order of these options than earlier versions, but some order-dependence remains. If you see error messages about unrecognized options, please try again using the exact order listed in the documentation.

Commands may extend over several input lines by ending each line but the last with a backslash (\). The backslash must be the _last_ character on each line. The effect is as if the backslash and newline were not there. That is, no white space is implied, nor is a comment terminated. Therefore, commenting out a continued line comments out the entire command (see `comments`). But note that if an error occurs somewhere on a multi-line command, the parser may not be able to locate precisely where the error is and in that case will not necessarily point to the correct line.

In this document, curly braces ({}) denote optional arguments and a vertical bar (|) separates mutually exclusive choices. `gnuplot` keywords or help topics are indicated by backquotes or `boldface` (where available). Angle brackets (<>) are used to mark replaceable tokens. In many cases, a default value of the token will be taken for optional arguments if the token is omitted, but these cases are not always denoted with braces around the angle brackets.

For on-line help on any topic, type help followed by the name of the topic or just help or `?` to get a menu of available topics.

The new `gnuplot` user should begin by reading about `plotting` (if on-line, type `help plotting`).

See the simple.dem demo, also available together with other demos on the web page http://www.gnuplot.info/demo/simple.html