Software to make line graph, Like Excel?

[tonyjeffs]

Is there any software that will convert a series of numbers into a simple line graph, the same as Excel, but allowing me to use a lot more numbers?

I'm writing a program in c to convert a sinewave, or any wave, into a triangular wave.
I've sort of done it, but there is noise in my triangular wave output if the input is of varying frequency, and I don't know for certain why. It is very hard to tell by looking at a page of numbers, so I want to look at a graphical representation of my triangular wave and see what's going wrong. The data, the points on the graph, is too much for excel.

Thanks
Tony

 

[AlephZero]

Try gnuplot. http://www.gnuplot.info/

 

[nicksauce]

Matlab of course. Not free, though.

 

[tonyjeffs]

Gnuplot does the trick.
Matlab - £3,000. The opposite of free!

Many thanks
Tony

 

[EzGraphs]

R is open source software and a library called ggplot2 allows you to make publication quality graphs. A bunch of examples are available at http://www.r-chart.com/" .