[pstricks] \psLCNode variant

[Michael Sharpe]

Herbert,

Here is a small variant of your \psLCNode macro from pstricks-add. I  
have found it useful because it allows the coefficients in the linear  
combination (#3) to be specified in any manner acceptable as  
\SpecialCoor coordinates.  (The Postscript form is especially useful  
in practice.)

\makeatletter
% build the linear combination #3[1]]*#1+#3[[2]]*#2=#4
\def\psLCNodeVar(#1)(#2)(#3)#4{%
   \pst at getcoor{#1}\pst at tempA%
   \pst at getcoor{#2}\pst at tempB%
   \pnode(#3){tmpn at de}
   \pnode(!%
     \pst at tempA /YA exch \pst at number\psyunit div def
     /XA exch \pst at number\psxunit div def
     \pst at tempB /YB exch \pst at number\psyunit div def
     /XB exch \pst at number\psxunit div def %stack now empty
     \psGetNodeCenter{tmpn at de}\space tmpn at de.x tmpn at de.y
     XA tmpn at de.x mul XB tmpn at de.y mul add
     YA tmpn at de.x mul YB tmpn at de.y mul add){#4}%
}
\makeatother


Michael