Generate line and bar charts

[Ashok Rathi]

	I have a program (in "C") which generates some statistics. I want
to plot theses statistics onto a line chart. Are you aware of the most
convenient utility that can be accessed by the "C" program which can
plot onto a line chart. For example:

	X        Y
	-        -

       100      10
       200      15
       300      35
       400      25


	  |
	40|
	  |			x
	30|
	  |				x
	20|
	  |		x
	10|	x
	  |
	 0|---------------------------------------
		100	200	300	400

	
	Eventually I need a hard copy of all the charts. We have
a fairly decent printing facility. Any suggestions? Thanks in advance!