move baxter end effector position regardless of orientation

edit

I downloaded these codes from the link https://www.google.co.uk/url?sa=t&rct...

first code ik_solver.py import argparse import sys

import rospy

from geometry_msgs.msg import (
    PoseStamped,
    Pose,
    Point,
    Quaternion,
)
from std_msgs.msg import Header

from baxter_core_msgs.srv import (
    SolvePositionIK,
    SolvePositionIKRequest,
)


def ik_solve(limb, pos, orient):
    #~ rospy.init_node("rsdk_ik_service_client")
    ns = "ExternalTools/" + limb + "/PositionKinematicsNode/IKService"
    iksvc = rospy.ServiceProxy(ns, SolvePositionIK)
    ikreq = SolvePositionIKRequest()
    print "iksvc: ", iksvc
    print "ikreq: ", ikreq
    hdr = Header(stamp=rospy.Time.now(), frame_id='base')
    poses = {
        str(limb): PoseStamped(header=hdr,
            pose=Pose(position=pos, orientation=orient))}

    ikreq.pose_stamp.append(poses[limb])
    try:
        rospy.wait_for_service(ns, 5.0)
        resp = iksvc(ikreq)
    except (rospy.ServiceException, rospy.ROSException), e:
        rospy.logerr("Service call failed: %s" % (e,))
        return 1
    if (resp.isValid[0]):
        print("SUCCESS - Valid Joint Solution Found:")
        # Format solution into Limb API-compatible dictionary
        limb_joints = dict(zip(resp.joints[0].name, resp.joints[0].position))
        print limb_joints
        return limb_joints
    else:
        print("INVALID POSE - No Valid Joint Solution Found.")

    return -1

The second code movement_commands.py

import baxter_interface
import baxter_external_devices
import rospy
import ik_solver
from geometry_msgs.msg import (    
    Point,
    Quaternion,
)


# Moves relative to current Position
def moveRel(x,y,z):
    pose = left.endpoint_pose()
    print "current pose: ", pose
    curX = pose["position"].x
    curY = pose["position"].y
        curZ = pose["position"].z
    newX = curX + x
    newY = curY + y
    newZ = curZ + z
    loc = Point(newX,newY,newZ)
    print "loc: ", loc    
    faceDown = Quaternion( 0.0, 0.0, 0.5, 0.0)
    #print "orient: ", faceDown
    limb_joints = ik_solver.ik_solve('left', loc, faceDown)
    prev = loc
    if limb_joints != -1:
        print "limb_joints: ", limb_joints
        print "moving arm to limb_joints joints"
        left.move_to_joint_positions(limb_joints)


# Takes a Point()
def moveTo(goal):
    loc = goal
    faceDown = Quaternion( 0.0, 0.0, 0.5, 0.0)
    #print "loc: ", loc    
    #print "orient: ", orient[1]
    limb_joints = ik_solver.ik_solve('left', loc, faceDown)
    prev = loc
    if limb_joints != -1:
        #print "limb_joints: ", limb_joints
        #print "moving arm to goal limb_joints joints"
        print "  "
        print "  "
        print "  "
        left.move_to_joint_positions(limb_joints)

rospy.init_node('move_left_hand')
rs = baxter_interface.RobotEnable()
rs.enable()

left = baxter_interface.Limb('left')
leftGripper = baxter_interface.Gripper('left')
pose = left.endpoint_pose()
b = True
pos = pose.popitem()
orient = pose.popitem()
prev = pos[1]

left.set_joint_position_speed(1.0)

print "-----------------------------------"
pose = left.endpoint_pose()
print "current pose: ", pose
s = raw_input("Press q to run ... ")
if s == 'q':
    moveTo(Point(-0.008758931559827073, 0.4037057092838424, 1.1405580898861356))
    print left.endpoint_pose()

The second code movement_commands.py has a function moveTo where you put the position of the end effector and it moves there but you also have to put the orientation which is a quaternion. I don’t completely understand how the orientation works so I want to ask if there is a way to only put the position of the I want the end effector to be at without having to use the orientation.