conversions.py

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# Author: Ioan Sucan

import StringIO
from moveit_commander import MoveItCommanderException
from geometry_msgs.msg import Pose, PoseStamped, Transform
import rospy
import tf

def msg_to_string(msg):
    buf = StringIO.StringIO()
    msg.serialize(buf)
    return buf.getvalue()

def msg_from_string(msg, data):
    msg.deserialize(data)

def pose_to_list(pose_msg):
    pose = []
    pose.append(pose_msg.position.x)
    pose.append(pose_msg.position.y)
    pose.append(pose_msg.position.z) 
    pose.append(pose_msg.orientation.x)
    pose.append(pose_msg.orientation.y)
    pose.append(pose_msg.orientation.z)
    pose.append(pose_msg.orientation.w)
    return pose

def list_to_pose(pose_list):
    pose_msg = Pose()
    if len(pose_list) == 7:
        pose_msg.position.x = pose_list[0]
        pose_msg.position.y = pose_list[1]
        pose_msg.position.z = pose_list[2]
        pose_msg.orientation.x = pose_list[3]
        pose_msg.orientation.y = pose_list[4]
        pose_msg.orientation.z = pose_list[5]
        pose_msg.orientation.w = pose_list[6]
    elif len(pose_list) == 6: 
        pose_msg.position.x = pose_list[0]
        pose_msg.position.y = pose_list[1]
        pose_msg.position.z = pose_list[2]
        q = tf.transformations.quaternion_from_euler(pose_list[3], pose_list[4], pose_list[5])
        pose_msg.orientation.x = q[0]
        pose_msg.orientation.y = q[1]
        pose_msg.orientation.z = q[2]
        pose_msg.orientation.w = q[3]
    else:
        raise MoveItCommanderException("Expected either 6 or 7 elements in list: (x,y,z,r,p,y) or (x,y,z,qx,qy,qz,qw)")
    return pose_msg

def list_to_pose_stamped(pose_list, target_frame):
    pose_msg = PoseStamped()
    pose_msg.pose = list_to_pose(pose_list)
    pose_msg.header.frame_id = target_frame
    pose_msg.header.stamp = rospy.Time.now()
    return pose_msg

def transform_to_list(trf_msg):
    trf = []
    trf.append(trf_msg.translation.x)
    trf.append(trf_msg.translation.y)
    trf.append(trf_msg.translation.z) 
    trf.append(trf_msg.rotation.x)
    trf.append(trf_msg.rotation.y)
    trf.append(trf_msg.rotation.z)
    trf.append(trf_msg.rotation.w)
    return trf

def list_to_transform(trf_list):
    trf_msg = Transform()
    trf_msg.translation.x = trf_list[0]
    trf_msg.translation.y = trf_list[1]
    trf_msg.translation.z = trf_list[2]
    trf_msg.rotation.x = trf_list[3]
    trf_msg.rotation.y = trf_list[4]
    trf_msg.rotation.z = trf_list[5]
    trf_msg.rotation.w = trf_list[6]
    return trf_msg