how to graph

1. open cargoflow.dotall (in docs)

2. isolate HIS economy, delete incomplete ones

2.5. remove quotes in 'the_lot'

3. save as .dot file

4. use command 

dot -Tps his2.dot -o his2.ps

to convert to .ps file

5. copy file to windows pc with nas or something

6. use EPS viewer to save .ps as .jpg (gif may crash). May necessitate cropping and fiddling. multiply width and height by 10. 7500 width works