So it's not a graph of how your rig actually performs, just a graph of whattomine results? I'm not so sure that's going to be accurate. You should modify your script to poll the API of the mining software for accurate sample data, inject that into whattomine's calculator for a point in time profitability graph.
If you aren't selling you mined coins at that exchange rate at that exact moment, then the profitability/income graph means nothing. It's not until you actually sell a coin that you can count profits.
It shows monthly profit of every card with optimal settings, based on current profit. Of course difficulty and prices change, there is no way to predict that. It is very useful to know what is best to mine with the cards you have though, and what coins tend to be best for your hardware. If you are planning on hodling less profitable coins you think will rise more, you are still better off mining for best profit and trading for other coins.
