Next time, when you refer a docs, you could give a link where you found it. Also as I can not read your mind, you might want to show code on things you have done, so I would not need to guess. Currently not having my WP8 environment with this machine so can not test how the API would work.
Anyway, as the value set there is point, i.e. it has X & Y values, I would not thing that value max to 1 would have any difference really. The docs are bad, but I would assume that the change could be actually in visible pixels, so would suggest trying out higher value.
The 0-1 thing probably comes from earlier experience with viewports of various graphical libraries. So it is not a mark of insanity or something like that.
However I have not found reference to viewports in this context, and especially the paragraph
Originally Posted by Remarks
After you set the value of the TransformCenter property for the Map control, the Center property continues to return the previous center until you set the Center to the same value as the TransformCenter.
Was thinking the same (that it would be geo coordinate), but was thinking to trust the actual definition , in which the value is point (i.e. its int,int point, where geocoordinate would be double,double +additional information one..)
I'm sorry for over reacting, but after your first post about polyline I was "confused"
The value must be between 0 and 1 else you get an exception. I would assume that it is a pivot center of heading rotation in %. This is what I'm looking for. But it does not work.