# This is a text data file.  It doesn't need to begin with a
# comment, although this one does.  Comments and empty lines
# are ignored in text data files.

-1 1	# This is row 1.  It contains two columns.
0    0	# This is row 2.  Columns don't need to be lined up neatly.
  1   1 # Row 3.  Whitespace separates columns and is otherwise ignored.
1.5 2.25# Row 4. Most common formats for base 10 numbers are acceptable.
	# Note, however, that only "." can be used to separate
	# the integer and fractional parts ("," is treated as a
	# column separator).

2 4	# Row 5 (the empty and comment lines aren't counted.)
2.5 6.25 8  # The "8" is ignored, since row 1 has only 2 columns.
3 9
4,16	# Comma-separated value (CSV) format is acceptable.
"5","25"# Quoted CSV format is also acceptable. 
6 3.6e1	# Standard notation for floating-point numbers is acceptable.
7 490e-1# Here's another, with a negative exponent.
8 64.
9 +81.0	# The "+" is redundant, but acceptable.
10 1e2

# There can be more comments at the end ....