# Revision history [back]

### tf Python API transform points

Hi

The TF documentation mentions that there are methods to convert points from one frame to another. I am currently using the python tf api.

I have a list of [x,y,z] points in the sensor frame and I want to transform these points into the map frame.

calling this

 (tran, rot) = self.tf_listener.lookupTransform('/body', '/map', rospy.Time(0.0))


gives a translation vector and a quaternion for the rotation. I am not really familiar with quaternions... but I heard they are hard...

Anyway Is there a method in the python api to convert my vector of points to another frame? I noticed in the c++ tf api there was a function called transformPoint. Is this what I need?

My other idea is to use the transformation.py module to convert the quaternions and the translation vector to a homogeneous transformation matrix and transform the vector of points manually. (by using the transformations.py module) http://wiki.ros.org/geometry/RotationMethods#transformations.py

 2 retagged

### tf Python API transform points

Hi

The TF documentation mentions that there are methods to convert points from one frame to another. I am currently using the python tf api.

I have a list of [x,y,z] points in the sensor frame and I want to transform these points into the map frame.

calling this

 (tran, rot) = self.tf_listener.lookupTransform('/body', '/map', rospy.Time(0.0))


gives a translation vector and a quaternion for the rotation. I am not really familiar with quaternions... but I heard they are hard...

Anyway Is there a method in the python api to convert my vector of points to another frame? I noticed in the c++ tf api there was a function called transformPoint. Is this what I need?

My other idea is to use the transformation.py module to convert the quaternions and the translation vector to a homogeneous transformation matrix and transform the vector of points manually. (by using the transformations.py module) http://wiki.ros.org/geometry/RotationMethods#transformations.py