3.10.1 if-old

Through gnuplot version 4.4, the scope of the if/else commands was limited to a single input line. This has been replaced by allowing a multi-line clause to be enclosed in curly brackets. The old syntax is still honored by itself but cannot be used inside a bracketed clause.

If no opening "{" follows the ‘if‘ keyword, the command(s) in <command-line> will be executed if <condition> is true (non-zero) or skipped if <condition> is false (zero). Either case will consume commands on the input line until the end of the line or an occurrence of ‘else‘. Note that use of ‘;‘ to allow multiple commands on the same line will _not_ end the conditionalized commands.

Examples:

      pi=3
      if (pi!=acos(-1)) print "?Fixing pi!"; pi=acos(-1); print pi

will display:

      ?Fixing pi!
      3.14159265358979

but

      if (1==2) print "Never see this"; print "Or this either"

will not display anything.

else:

      v=0
      v=v+1; if (v%2) print "2" ; else if (v%3) print "3"; else print "fred"

(repeat the last line repeatedly!)

See reread for an example of using if and reread together to perform a loop.

This document was generated on April 4, 2012 using texi2html 5.0.