| Author | Message | ||
     Klaas Faber (faber) New member Username: faber Post Number: 5 Registered: 9-2003 |
Hi! When developing a permutation test for a complex problem like component selection, one has to make a choice for test statistic. Fit of y would have been another choice (which I investigated as well; it gives similar results). The idea behind the choice we finally ended up with, is that it leads to a t-test for PCR (normalized scores) under standard regression assumptions (no noise in x). This permutation test therefore generalizes that particular t-test to (1) more general circumstances and (2) other component-based calibration methods. Klaas | ||
| Christian Mora (cmora) Junior Member Username: cmora Post Number: 10 Registered: 2-2007 |
OK, I found it: it was the inner product of the scores and the Y vector. Thanks anyways | ||
| Ian Michael (admin) Board Administrator Username: admin Post Number: 11 Registered: 1-2006 |
In case anyone wants to read the article, it can be downloaded free-of-charge from http://www.spectroscopyeurope.com/td_col.html#18_5. | ||
| Christian Mora (cmora) Junior Member Username: cmora Post Number: 9 Registered: 2-2007 |
I'm sorry: Spectroscopy Europe October/November 2006. Thanks | ||
| Howard Mark (hlmark) Senior Member Username: hlmark Post Number: 113 Registered: 9-2001 |
Christian - in which periodical? JNIRS is only up to Vol. 15, and NIR News is only up to issue #4 of Vol. 18. Unless it's some other journal, it hasn't been published yet!! \o/ /_\ | ||
| Christian Mora (cmora) Junior Member Username: cmora Post Number: 8 Registered: 2-2007 |
Dear List Members; In Tony Davies's article Vol 18 No 5 2006, Faber and Rajko discussed the permutation test as an approach to evaluate the significance of the components of a PLS model. They say:"For each of these random models, a test statistic is calculated" Does anyone know what is the actual "test statistic" they mention? Thanks CMora |