Hi Serge, It is our intent to get planes (and centroids) in there as measurables after a few last improvements to axis support. Hopefully soon but unfortunately there are a lot of demands on my time. As a stopgap I've attached a script that measures atom/axis distances/ angles to a plane. You select either 4 or 5 atoms (select the 3 plane atoms last) and running the script will report the distance/angle in the Reply Log. It was relatively easy to write the script because Chimera has a built-in primitive for determining 3-point planes. But work needs to be done to easily support 4+ point planes (currently the points need to be sorted into "clockwise" or "counter-clockwise" order -- don't ask!). Aside from selecting atom with the mouse, order can be guaranteed in an atom specifier by using '@' symbols to separate atoms rather than ','. So, the following command will select the atoms from left to right: sel :3.a@ne2@cg :6.a@ce2@ce1@cg whereas the following command wouldn't guarantee the selection order of the first two atoms or the last three: sel :3.a@ne2,cg :6.a@ce2,ce1,cg --Eric On Sep 5, 2008, at 9:11 AM, Serge Gorelsky wrote:

Hello,

would it be possible to add the two following features to the "Tools/Structure Analysis" menu of UCSF Chimera: the distance between atom A and a plane of other 3 atoms B,C,D ("the height of a trigonal pyramid with atoms B, C, D at the base ") and the angle between an axis (defined by atoms A and B) and the plane B-C-D ?

Thank you very much in advance. -- Best regards, Serge Gorelsky (a Chimera user since 2005)