Re: [MORPHMET] fitting lines to allometric plots?

[Emma Sherratt]

Hi Christy,

I think the "PredLine" functionality of *geomorph's* procD.allometry()
function, following the Adams & Nistri 2010 BMC paper is a safer approach.
We have to remember we are dealing with multivariate data here and a
multivariate regression where the Y axis is a univariate summary, and the
"line" is just an approximation of the trajectory in a multidimensional
space. I think that putting such a line would mislead people and wouldn't
be accurate.

Em

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On 21 December 2016 at 15:12, Christy Hipsley 
wrote:

> Hi all,
>
> This is a fairly simple question, but one that I am unsure of - is it
> appropriate to fit lines to plots of allometric scores, for example
> regression score or common allometric component (CAC) vs size, or the first
> residual shape component (RSC) vs CAC? If the scores represent individuals
> from different groups or species, does it make sense to add a line of best
> fit to each group to visualize trends? I've noticed in other papers that
> lines are not used, so I'm wondering if this is somehow "wrong". I realize
> the line itself is not the regression line, but if it's only used for
> visual comparison, is that technically okay?
>
> Thanks for any feedback,
> Christy
>
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[MORPHMET] fitting lines to allometric plots?

[Christy Hipsley]

Hi all,

This is a fairly simple question, but one that I am unsure of - is it 
appropriate to fit lines to plots of allometric scores, for example 
regression score or common allometric component (CAC) vs size, or the first 
residual shape component (RSC) vs CAC? If the scores represent individuals 
from different groups or species, does it make sense to add a line of best 
fit to each group to visualize trends? I've noticed in other papers that 
lines are not used, so I'm wondering if this is somehow "wrong". I realize 
the line itself is not the regression line, but if it's only used for 
visual comparison, is that technically okay?

Thanks for any feedback,
Christy

-- 
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