At 07:56 PM 5/30/2012, Troy Henderson wrote:

Well then in case anyone needs such a transformation, I've constructed the (non-unique) transformation T

...

t:=angle(f,e); q:=e++f; p:=(c*f-d*e)/q; s:=(c*e+d*f)/(q**2); transform T; T:=identity rotated t xscaled p yscaled q slanted s shifted (a,b);

This yields T=(a,b,c,d,e,f).

You can implement something like what you wanted directly because, just as you can write equations for the parts of a pair, you can also write equations for the parts of a transform: vardef mktransform (expr a,b,c,d,e,f) = save T_; transform T_; xpart T_ = a; ypart T_ = b; xxpart T_ = c; xypart T_ = d; yxpart T_ = e; yypart T_ = f; T_ enddef; After this transform T; T := mktransform (1,2,3,4,5,6); show T; produces:

...

(1,2,3,4,5,6)

Regards, Dan Daniel H. Luecking Department of Mathematical Sciences Fayetteville, Arkansas http://www-cs-faculty.stanford.edu/~knuth/iaq.html