Hi Olaf
Thanks for the kind words - glad you're liking it!
is there a way to view a roast temperature curve as graph instead of node list?
At the moment, only in the roast console. I originally wanted the list views to have the curves as icons, but quickly realized that would not be good for memory management (that would necessitate loading every node into memory), so for speed and performance I decided against it. I agree - there should be a way to view the curve in the curve details screen, though. I want to address that soon.
can an existing curve be used as target or background profile
Yes. First, make sure the graph is set to display past curves. Tap the round "i" button near the graph and set "Past Curves" transparency to a value that you like. Roastmaster will attempt to display the few most recent curves overlaid onto each other, in addition to your current curves, to give you an idea of where things should be going in your current roast. (past curves are displayed most recent first)
Now, this data will, by default, be populated based on the selected buttons in the selector strip. If you want to manually target one or more roasts, tap the magnifying glass icon on that strip to turn it over, then the green "+" button to add or remove roasts from the graph.
Once you've got the graph populated with the data you want, you can hone in even further on curve data with the full screen graph. The full screen graph only displays the curve of 1 roast in addition to the current curves. It chooses that based on what is being displayed in the standard graph, opting for the highest rated, then most recent roast, if more than 1 are being shown. (Crack times and duration are averaged)
About data-logging… The core of data-logging has been complete for about a month in the development version. I've had to backtrack a bit, and beef up a few other areas of the app to support that. An auto-logging environment, as you know, generates a lot more data, and iOS devices have certain memory and speed limitations. I've concentrated a lot of effort into making curves "smarter", and eliminated the need to load curves into memory when performing past roast matching for the graph. It's all under-the-hood stuff at this point, but necessary now that the number of nodes can now grow quite large.
I only put the video up for a short while. I worried that non-english speakers would have no way of knowing that it was demonstrating a feature from a future development version, not the current version on the app store, and be misled a bit. I've got a number of tutorial videos in the works that I want to get back to work on once data logging goes live, but I'll probably use vimeo for that - not quite sure yet.
A few notes about curves and profiles, since we're on that topic. I've beefed up programs and profiles a bit for the update. There will now be two sections in profiles and programs that can hold curves. The existing section will hold control curves, and target temp curves, just as it does now. These will be visible in the roast, but still reside with the profile or program. The new section, will be for holding "Curve templates". These will be blank curve templates that will spawn empty curves within every roast that uses that profile or program, for the purpose of recording data. These curves will only reside in the roast, and allow full data entry without having to recreate them every time. The end result is, that no matter how many curves you track, they're all set up and ready to roll with just two taps. It's a lot easier.
So, as you're getting used to the app, if you're using profiles or programs, store control curves and target reading curves only there. Then, create your reading curves for recording live data in the roast itself. When the update comes out, this workflow can be easily adjusted to allow for a lot more automation.
Let me know any questions you have - I can always help - and thanks for posting!
Kind regards
Danny Hall