Three versions of modern Europe PCA from 2022 and 2024 scientific papers

[Russki]

All three look different from each other, and technically none of them are "wrong".

Open images in a new tab and zoom in to observe them in detail.

AL = Albania
BE = Belgium
BG = Bulgaria
BIH = Bosnia and Herzegovina
BLR = Belarus
COR = Corsica
DK = Denmark
ENG and E = England
ES = Spain
EST = Estonia
FI and FIN = Finland
FR = France
GER = Germany
GR = Greece
HR = Croatia
HU - Hungary
IE = Ireland
IT = Italy
LT = Lithuania
LV = Latvia
ME = Montenegro
MK = North Macedonia
NL and NED = Netherlands
NO = Norway
PL = Poland
PT = Portugal
RKS = Kosovo
RO = Romania
RS = Serbia
RU = Russia
SAR = Sardinia
SC = Scotland
SE = Sweden
SI = Slovenia
SIC = Sicily
SK = Slovakia
UA = Ukraine
WA and W = Wales


https://sun9-79.userapi.com/impg/SX9s1OhgkfkAo3Yh9XhpsRxmCCHeVaDc0oyaOQ/fUCyo9UhAdk.jpg?size=1181x1036&quality=95&sign=cfb04e70672bcb8e12ce09ca4087179f&type=album
https://sun9-3.userapi.com/impg/AR9flmKCryJT36WvLyOnYn4zbGWIAQVZ9Txbyw/u6hquqGH2l8.jpg?size=844x807&quality=95&sign=2b64bb3ae7ac10f95b8cfadbc705b3a0&type=album
https://sun9-25.userapi.com/impg/jw1uQXHOHfCapLGqTq1ucJZhdA4W0N1B7jw5fg/IPV7l_Lfpe8.jpg?size=847x800&quality=95&sign=a6300e3586f8812e86c3929cbaa88d01&type=album





Sources:
https://www.nature.com/articles/s41586-022-05247-2
https://www.nature.com/articles/s41562-024-01888-7

[Russki]

Fourth


https://sun9-41.userapi.com/impg/tGWQBOfUQDGIIyaQ0SQSEBuznW7bKUnCMo-fOg/iwJL6CHHlzg.jpg?size=1490x1260&quality=95&sign=6f8f1faf1352dfb0b0ca9acda3676197&type=album

[rothaer]

All three look different from each other, and technically none of them are "wrong".
(...)

Exactly.

To fully be aware of the conditions I suggest to imagine a rotating 3D PCA.

At any time you can say stop and freeze the pic and you will have a technically correct 2D PCA. Also, you can always turn a 3D PCA to have two arbitraty points at the same location in 2D. You can make even 1,000 different and correct 2D PCAs out of a given 3D PCA.

All this loss of information is caused by breaking down 3 dimensions to 2 dimensions.

And now imagine that G25 coords give information for 25 dimensions...

[Gotse]

I will go off-topic, but how is it possible that there are so small number of results for East Europe comparing to West and North Europe?

[gixajo]

With the same data you can make a multitude of different PCAs, varying which components each axis refers to, or depending on which groups of coordinates you decide to add (as you add references, the shape and orientation of the different plots or clusters vary) without counting if you play with the conformation parameters of each PCA, or the number of dimensions in which it is projected (graphically this is somewhat limited)...

There is a paper that talks about all this, and that has been cited by several forum members on many occasions, in which they talk about the great flexibility that PCAs allow to represent plots. (I don't remember the title, although I have also used it for reference).

In theory, they are all valid, and in a general sense they all show the same "tendencies, If you know how to see it, of course...

[Dušan]

Fourth


https://sun9-41.userapi.com/impg/tGWQBOfUQDGIIyaQ0SQSEBuznW7bKUnCMo-fOg/iwJL6CHHlzg.jpg?size=1490x1260&quality=95&sign=6f8f1faf1352dfb0b0ca9acda3676197&type=album

Missing Moldova, Czechia and Austria.