4.18.1. Linear Transformation

geomTransf('Linear', transfTag, '-jntOffset', *dI, *dJ)

geomTransf('Linear', transfTag, *vecxz, '-jntOffset', *dI, *dJ)

This command is used to construct a linear coordinate transformation (LinearCrdTransf) object, which performs a linear geometric transformation of beam stiffness and resisting force from the basic system to the global-coordinate system.

transfTag (int)	integer tag identifying transformation
vecxz (list (float))	X, Y, and Z components of vecxz, the vector used to define the local x-z plane of the local-coordinate system. The local y-axis is defined by taking the cross product of the vecxz vector and the x-axis. These components are specified in the global-coordinate system X,Y,Z and define a vector that is in a plane parallel to the x-z plane of the local-coordinate system. These items need to be specified for the three-dimensional problem.
dI (list (float))	joint offset values – offsets specified with respect to the global coordinate system for element-end node i (the number of arguments depends on the dimensions of the current model).
dJ (list (float))	joint offset values – offsets specified with respect to the global coordinate system for element-end node j (the number of arguments depends on the dimensions of the current model).