There is also the GNUPlot application for science and computing. This is an open source application for plotting and simple math.
As it's a zip file, you don't need to install on PC, it's almost portable 
New: MBox Viewer (Mar 22, 2026), Platform 30.3 (Mar 29, 2026)
1,400+ portable packages, 1.2 billion downloads
Our costs have risen a bunch. Please donate if you can!
There is also the GNUPlot application for science and computing. This is an open source application for plotting and simple math.
As it's a zip file, you don't need to install on PC, it's almost portable 
Yeah, I have been using this, it's great - seems to work portably out of the box.