PO, Citizen's Platform, the center-right liberal (in the European economic sense) ruling party. Very pro-European, pro-German.
PiS, Law and Justice, mainstream right wing nationalist party, very Catholic, pro-Europe economically but fighting culture wars over in vitro, gay marriage and so on.
PSL, Polish People's Party, agrarian party with roots stretching back to before WWII. Represents rural interests.
SLD, Democratic Leftist Union, the post-Communist left that discredited itself horribly when last in power ten years ago (through corruption scandals) and is still in the political wilderness. Pro-EU, very much a modern European left party in terms of platform but dominated by faces from the bad old days.
It has done in flash, when flash was cool...
However, I do think the graphs are a bit misleading in that the x,y,z components are normalised in the figures, whereas actually y is far more significant than x or z.
> In our case, three initial left-singular vectors contribute 70.1%, 8.5%, and 3.6% of the total variance of R, respectively.
And thanks for sharing code as well!
I would love to see some CSV dump of the scrapped data, because this work might inspire others to experiment and do interesting things as well...
Edit: thinned it out to politicians who vote together > 75% of the time: http://imgur.com/NfxDY6H .
Layout = forceatlas2 and labeling is random due to a glitch (normally biggest node in a region.)
Blog at: https://voteviewblog.wordpress.com/