DoriC wrote:In Preferences under General what are the best settings for Middle calculations, Maximum calculations to use

For us ResMed users, Mark recommends Median for the Middle and 99% for Maximum -- at least, on my Mac, when I hover over the drop-down list for Middle Calculations, a little yellow help box pops up to say "Median is recommended for ResMed users", and when I hover over the drop-down for Maximum Calcs it says "ResMed users should probably use 99th Percentile for visual consistency".

Median is a number that half the values are at or below, and half the values are at or above. So if your leaks for a short time were 10, 10, 15, 125, 10, 12, 15, then the median leak would be 12. The mean, or normal average, would be about 28. Probably 12 gives as good a picture of what was going on as any one number can --

most of the time your leaks were reasonable.

The 99th percentile is a number that 99 percent of the numbers were at or below, and 1 percent were at or above. Basically this tells SleepyHead to ignore truly extreme numbers when it reports the maximum, as long as they are also extremely rare: if you have 995 Tidal Volume numbers, all between 100 and 1500, and 5 values of 2000, SleepyHead will report 1500 as the maximum.

DoriC wrote:Under Appearance, what settings for Overlay Flags and Graph Height. I don't know exactly how to set them.

At least on my Mac, if I set Overlay Flags to "Standard Bars", then I get colored lines going through the black flow rate lines. If I set Overlay Flags to "Top & Bottom Markers", then the event markers on the Flow Rate graph are little colored tick marks on the bottom of the graph, sitting on the line over the time numbers. If I zoom in on the graph by selecting a particular time period or by pressing the up arrow, then the bottom tick marks turn into the standard bars once the graph covers an hour or less of time.

Graph height controls how tall each graph is when you click on the

Reset button down in the lower left corner of the graph section, just to the right of the

100% button. The taller each graph, the fewer graphs you can see at once. For me, the default of 180 pixels lets me see four graphs at once. If I lower that to 150 pixels I can see five graphs at once, and 100 pixels gives me seven graphs. (SleepyHead will accept fewer than 100 pixels in the Graph Height box, but numbers under 100 just act like 100.)