waitForTransform

Wait until a transformation is available

waitForTransform will be removed in a future release. Use getTransform with a specified timeout instead. Use inf to wait indefinitely.

Syntax

waitForTransform(tftree,targetframe,sourceframe)

waitForTransform(tftree,targetframe,sourceframe,timeout)

Description

waitForTransform(tftree,targetframe,sourceframe) waits until the transformation between targetframe and sourceframe is available in the transformation tree, tftree. This functions disables the command prompt until a transformation becomes available on the ROS network.

waitForTransform(tftree,targetframe,sourceframe,timeout) specifies a timeout period in seconds. If the transformation does not become available, MATLAB^® displays an error, but continues running the current program.

Examples

Wait for Transformation Between Robot Frames

Connect to the ROS network. Specify the IP address of your network.

rosinit('192.168.17.129')

Initializing global node /matlab_global_node_48383 with NodeURI http://192.168.17.1:54695/

Create a ROS transformation tree.

tftree = rostf;

Wait for the transformation between the target frame, /camera_depth_frame, and the source frame, /base_link, to be available. Specify a timeout of 5 seconds.

waitForTransform(tftree,'camera_depth_frame','base_link',5);

Get the transformation.

tform = getTransform(tftree,'camera_depth_frame','base_link');

When you are finished, disconnect from the ROS network.

rosshutdown

Shutting down global node /matlab_global_node_48383 with NodeURI http://192.168.17.1:54695/

Input Arguments

tftree — ROS transformation tree

TransformationTree object handle

ROS transformation tree, specified as a TransformationTree object handle. You can create a transformation tree by calling the rostf function.

targetframe — Target coordinate frame

string scalar | character vector

Target coordinate frame, specified as a string scalar or character vector. You can view the available frames for transformation by calling tftree.AvailableFrames.

sourceframe — Initial coordinate frame

string scalar | character vector

Initial coordinate frame, specified as a string scalar or character vector. You can view the available frames for transformation using tftree.AvailableFrames.

timeout — Timeout period

numeric scalar in seconds

Timeout period, specified as a numeric scalar in seconds. If the transformation does not become available, MATLAB displays an error, but continues running the current program.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• Supported only for the Build Type, Executable.

• Usage in MATLAB Function block is not supported.

Version History

Introduced in R2019b