SPM calculation for a row with a partial split

[lcantey]

The SPM calculation for a piece can be so far off it's almost pointless to display as the average. For example this row a couple of days ago it reported 22 as the average when the full splits were 22/24/27/26 and a 14 for the partial 27 meters as it spun down. The real result would be ~24.75 and I'd hope it would be at least a 24 or 25.

1/14/15 19:24 0:20:08 20:08.5 4510 22

1/14/15 19:24 0:20:08 05:00.0 1052 22
1/14/15 19:24 0:20:08 10:00.0 1157 24
1/14/15 19:24 0:20:08 15:00.0 1199 27
1/14/15 19:24 0:20:08 20:00.0 1076 26
1/14/15 19:24 0:20:08 20:08.5 27 14

Edit: I just noticed my quick row this morning reported a 21 SPM when my splits were 23/25/25/25 and a 9 for the last 21m.

[Citroen]

Take a simple average (over 5 splits) rounded down to the lower integer.

(22 + 24 + 27 + 26 + 14) / 5
113 / 5 = 22.6
rounded that's 22.

The PM2, PM3, PM4 & PM5 have ALWAYS done it that way. Yes it's insane, yes it's wrong and it doesn't match any sensible way to do the maths. But you won't get it changed. Trust me folks have been asking Concept2 to fix this since forever.

The bug in the code is that it assumes all splits are equal length even when there's that short run down split for the last one.

You'll get marginally better results if you program a 20 minute workout rather than using "Just Row" for twenty minutes and a little bit (it's six seconds from when you stop rowing).

[lcantey]

Take a simple average (over 5 splits) rounded down to the lower integer.

(22 + 24 + 27 + 26 + 14) / 5
113 / 5 = 22.6
rounded that's 22.

The PM2, PM3, PM4 & PM5 have ALWAYS done it that way. Yes it's insane, yes it's wrong and it doesn't match any sensible way to do the maths. But you won't get it changed. Trust me folks have been asking Concept2 to fix this since forever.

The bug in the code is that it assumes all splits are equal length even when there's that short run down split for the last one.

You'll get marginally better results if you program a 20 minute workout rather than using "Just Row" for twenty minutes and a little bit (it's six seconds from when you stop rowing).

I understood how it was calculating it but it's just so crazy it's hard to believe. If nothing else throw away partial splits or at least if it's substantially shorter that a full one would have been. It's a few bytes of programming that they could put in as one of those improvements that were coming in the future since the increased capacity of the PM4 was announced.

I usually do pick a set distance for my 30min or 10k rows but sometimes in the morning I just hop on and Just Row assuming one of the kids will come out and need something.

[jamesg]

Averages are always to be treated with suspicion, but this is certainly a fine example of mixing average rates and rounding (twice in this case).

Doing four 5-minute pieces wouldn't you be interested in more detail anyway? Watts/Rating and Watts/HR range could tell you something.

For example:
m Rate W Work
1052 22 121 5,5
1157 24 161 6,7
1199 27 179 6,6
1076 26 129 5,0