If you have Python installed on your system, you can use use the Matlab python call functionality to read in such R files.
Firstly, ensure that you have installed the Python package pyreadr onto your system; this package reads/writes R RData and Rds files into/from pandas data frames, and does not require R to have been installed, not any other external dependencies installed.
Then you can load in matlab via the command:
dict = py.pyreadr.read_r(<path to rda file>);
As it stands the variable "dict" will be a Python OrderedDict, so to use data it contains you need to create a matlab array as follows:
result=double(dict{<key>}.values);
where <key> is the string defining which key of the pandas frame dict you wish to extract.
If in doubt, check which keys the imported panda frame has by running the command:
dict.keys()
Once you have found the key of interest, you may further check the complete properties of the data stored under this key by running the command:
dict{<key>}
