Making graphs

Rebol is fantastic to render graphs, with one line of code you can create wonderful graphs.
First of all you must know that in all programming languages coordinates on windows are to the right and to the bottom like this:

so we must remind us to flip vertical our graph.
First of all we must have some data to display

my-data: [ 10 20 30 40 50 200 190 220 60 150 ]

then we must give a sequence to these data, making them pair data to plot on the graph:
tempg:   [ 0x0 ]
temp: 0
foreach item my-data [
    temp: temp + 10
    append tempg (as-pair temp item)    
    ]

then we can use the grid effect to a 300x300 box. After the grid command you put the distance of the x and y grid and the offset (put always 0x0):

my-data: [10 20   30 40 50 200 190 220 60 150 ]
tempg:   [0x0]
temp: 0
foreach item my-data [
    temp: temp + 10
    append tempg (as-pair temp item)    
    ]
lay:   compose/deep [box 300x300 effect [grid 10x10 0x0 draw [pen red   LINE-WIDTH 3   line (tempg) ] flip 0x1   ] ]
view layout [
    title "My graph"
    panel lay ;tricky!!!
    ]

You can add any DRAW effect to your graph: arrows, spline or whatever you wish:

If you need more complex graph, you can use the q-plot library; you can download the library from here: http://www.rebol.org/view-script.r?script=q-plot.r
There is a fantastic guide here: http://www.rebol.org/view-script.r?script=ez-plot.r
I just upload here some examples: