GNUPlot Manual

62 gnuplot 4.0 36 SET-SHOW
set datafile missing {""}
show datafile missing
unset datafile
Example:
# Ignore entries containing IEEE NaN ("Not a Number") code
set datafile missing "NaN"
Example:
set datafile missing "?"
set style data lines
plot ’-’
1 10
2 20
3 ?
4 40
5 50
e
plot ’-’ using 1:2
1 10
2 20
3 ?
4 40
5 50
e
plot ’-’ using 1:($2)
1 10
2 20
3 ?
4 40
5 50
e
The first plot will recognize only the first datum in the "3 ?" line. It will use the single-datum-on-a-line
convention that the line number is "x" and the datum is "y", so the point will be plotted (in this case
erroneously) at (2,3).
The second plot will correctly ignore the middle line. The plotted line will connect the points at (2,20)
and (4,40).
The third plot will also correctly ignore the middle line, but the plotted line will not connect the points
at (2,20) and (4,40).
There is no default character for missing, but in many cases any non-parsible string of characters found
where a numerical value is expected will be treated as missing data.
36.14.2 Set datafile separator
The command set datafile separator "" tells gnuplot that data fields in subsequent input
files are separated by rather than by whitespace. The most common use is to read in csv
(comma-separated value) files written by spreadsheet or database programs. By default data fields are
separated by whitespace.
Syntax:
set datafile separator {"" | whitespace}
Examples:
# Input file contains tab-separated fields
set datafile separator "\t"
# Input file contains comma-separated values fields
set datafile separator ","