search

Search ROS network for parameter names

Syntax

pnames = search(ptree,searchstr)

[pnames,pvalues] = search(ptree,searchstr)

Description

pnames = search(ptree,searchstr) searches within the parameter tree ptree and returns the parameter names that contain the specified search string, searchstr.

[pnames,pvalues] = search(ptree,searchstr) also returns the parameter values.

The following ROS data types are supported as values of parameters. For each ROS data type, the corresponding MATLAB^® data type is also listed:

• 32-bit integers — int32

• Booleans — logical

• doubles — double

• strings — string scalar, string, or character vector, char

• lists — cell array

• dictionaries — structure

Examples

Search for ROS Parameter Names

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

rosinit('192.168.17.128')

Initializing global node /matlab_global_node_48144 with NodeURI http://192.168.17.1:54848/

Create a parameter tree.

ptree = rosparam;

Search for parameter names that contain 'gravity'.

[pnames,pvalues] = search(ptree,'gravity')

pnames = 1×3 cell array
    {'/gazebo/gravity_x'}    {'/gazebo/gravity_y'}    {'/gazebo/gravity_z'}

pvalues = 3×1 cell array
    {[      0]}
    {[      0]}
    {[-9.8000]}

Input Arguments

ptree — Parameter tree

ParameterTree object handle

Parameter tree, specified as a ParameterTree object handle. Create this object using the rosparam function.

searchstr — ROS parameter search string

string scalar | character vector

ROS parameter search string specified as a string scalar or character vector. The search function returns all parameters that contain this character vector.

Output Arguments

pnames — Parameter values

cell array of character vectors

Parameter names, returned as a cell array of character vectors. These character vectors match the parameter names in the ROS master that contain the search character vector.

pvalues — Parameter values

cell array

The following ROS data types are supported as values of parameters. For each ROS data type, the corresponding MATLAB data type is also listed:

• 32-bit integers — int32

• Booleans — logical

• doubles — double

• strings — string scalar, string, or character vector, char

• lists — cell array

• dictionaries — structure

Base64-encoded binary data and iso 8601 data from ROS are not supported.

Limitations

Base64-encoded binary data and iso 8601 data from ROS are not supported.

Extended Capabilities

C/C++ Code Generation

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

This function supports C/C++ code generation with the limitations:

• Retrieving values is not supported.

Version History

Introduced in R2019b