Summation

A summation expression has the form
     sum [<var> = <start> : <end>] <expression>
var is treated as an integer variable that takes on successive integral values from start to end. For each of these, the current value of expression is added to a running total whose final value becomes the value of the summation expression. Examples:
     print sum [i=1:10] i
         55.
     # Equivalent to plot 'data' using 1:($2+$3+$4+$5+$6+...)
     plot 'data' using 1 : (sum [col=2:MAXCOL] column(col))
It is not necessary that expression contain the variable var. Although start and end can be specified as variables or expressions, their value cannot be changed dynamically as a side-effect of carrying out the summation. If end is less than start then the value of the summation is zero.

Build Daemon user 2017-01-08