We're using cookies to make this site more secure, featureful and efficient.

Issue 452: Dance intensity

Object
Nothing in Common (Dance)
Submitter
Heiko
Assigned to
Anselm Lingnau
Priority
Normal
Disposition
Ignored
Description

Hi Anselm, hi Eric,

I am not quite sure how the whole dance is actually computed (though the theory is clear from the discussion):

88 88 88 88 = 100% (1 turn), 69% (whole dance)

The one turn number is clear - both couples are dancing all the time.

However, since that dances is a 2-cpl dance in a 3-cpl set (as stored in the SCDDB), I would expect the whole-dance-intensity to be 66.666% (or 67% rounded), but not 69%.

Any ideas on that?

Or does the computation still assumes 4 times through (as in Eric’s draft suggestion), even though SCDDB stores the true number anway and the numbers would thus be available?

Cheers, Heiko

Previous Actions

  • Date  May 5, 2014, 11:31 a.m.
  • User  Unknown

New issue submitted

  • Date  May 5, 2014, 11:48 a.m.
  • User  Anselm Lingnau (anselm)

Assigned changed to »anselm« (previously »None«)
Disposition changed to »Being handled« (previously »New«)

Right now the only »computation« the database does is that of the per-turn dance intensity, from the per-position activity counts that are part of Eric’s crib file but do not show up in the database. Everything else is straight from Eric’s crib file.

I agreed with Eric that the database should calculate all intensities from the »raw data« in the crib file (in effect, the »88 88 88 88« bit), not only to be consistent but also to make it easier to add dance intensities for dances that are not part of Eric’s crib collection. This is reasonably straightforward, and the only tricky bit is figuring out the number of turns a dance is actually danced from the number of couples and set shape. (I presume this is where Eric’s calculations in his crib file went wrong, but on the other hand I wouldn’t really worry about a 2% difference in whole-dance dance intensity.) The obvious way of addressing this is by pre-calculating the ratios (e.g., 4/4L = 100%, 3/4L = 69%, …) but »unfortunately« we store »number of active couples« and »set shape« separately, and the matter is more complicated than simply adding a column to the database.

  • Date  May 7, 2014, 1:08 a.m.
  • User  Eric Ferguson (EricFerguson)

Up to a month ago, Dance Intensities (DI) were calculated by hand from my “bar count list”, written into my master crib file, and nobody else saw them.

After they were uploaded to SCDDB, the “DI per turn” was added, and calculated by the database from the “Bar Count List”. The calculation software still has glitches.

The “Whole dance” DI still comes from my file. It differs from the “per turn” DI for most 2C and 3C dances by a reduction factor.

For 3C/4L: factor = 3/4 (one couple always stands out).

For 2C/RR: factor = 1 (no couple stands out)

For a 2C/4L, top pair starting: factor - 11/16 = 69%

2C/4L dance, all starting or middle pair starting: factor = 12/16 = 75%

2C/3L dance: factor = 2/3 = 67%

At present there are 1355 2C dances, of which 1077 2C/4L, 190 2C/RR, 44 2C/3L, and 44 others.

I agree with Anselm that it isn’t worth worrying about the difference 69% (2C/4L) and 67% (for the 44 2C/3L). The DI value is just meant to give a general impression. So it matters little if this calculation error is not fixed soon.

  • Date  Sept. 1, 2015, 9:50 p.m.
  • User  Eric Ferguson (EricFerguson)

Disposition changed to »Ignored« (previously »Being handled«)

Superseded by issue 772