Dear Marcello, Thank you for your response. I now performed the analysis suggested by you. Kind regards, Jens
On Monday, October 26, 2015 at 2:38:52 PM UTC+1, marcelo.cardillo wrote: > > If you want to use "free size effect data" I think it can be good idea > use the residuals of the regression between the PC and log(lengh), because > this residuals are new variables not explained by size. > > best > M > > 2015-10-26 9:42 GMT-03:00 Jens De meyer <[email protected] <javascript:> > >: > >> Dear, >> >> I have a question about EFDs, and was wondering if you could help me? I >> have performed a PCA on standardized EFDs (standardized for first harmonic, >> using SHAPE-software). The EFDs represented head shapes of eels which were >> given different diets (we compared three different diets). The results of >> the PCA indicated that PC1 was related to variation in head width, with >> high PC-scores being related to broader heads and vice versa. Next, we >> performed a linear regression on these PC-scores and log(length) of the >> three different diets and observed a size-effect in all three diets. >> Because of this, I wanted to divide the PC-scores by the total length of >> the studied eels. Then, we would perform an ANOVA on these length-corrected >> PC-scores between the different diets, as this would allow us to find out >> whether the mean head width of a certain diet is significantly broader than >> another diet. >> Therefore, my question to you is: Am I acutally allowed to divide these >> PC-scores by total length? >> Many thanks in advance! >> Kind regards, >> Jens De Meyer >> >> -- >> MORPHMET may be accessed via its webpage at http://www.morphometrics.org >> >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> > > > > -- > Dr.Marcelo Cardillo > IMHICIHU-CONICET-UBA > Saavedra 15, 5to piso cp (1083) > Teléfono: (011) 4953-8548 - Interno 212 > Buenos Aires. Capital Federal. Argentina > http://conicet.academia.edu/MarceloCardillo > -- MORPHMET may be accessed via its webpage at http://www.morphometrics.org To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
