Codegen respond with an error: "??Expected a character vector. "

When I use my training results of DDPG model to generate GPU code, there always respond an error. I followed the instruction "Deploy Trained Reinforcement Learning Policies" from help document, and it runs well in other exmples. Here is error report:

And return code:

>>codegen('-config','cfg','evaluatePolicy','-args',argstr,'-report');
??? Expected a character vector.
Code generation failed: View Error Report
Incorrect use of codegen

[Emmanouil Tzorakoleftherakis]

can you provide the rest of the code you are running? The doc page has some steps before running 'codegen'. For example what is 'cfg'? It seems there is a typo somewhere based on the error msg

[Haonan Ding]

"cfg" is a command from the sample in the topic “Deploy Trained Reinforcement Learning Policies” in the MATLAB help document, and here is the online link: "https://ww2.mathworks.cn/help/reinforcement-learning/ug/deploy-trained-reinforcement-learning-agents.html".

I have tried the second way "Generate Code Using MATLAB Coder", and it still has same issue.

cfg = coder.gpuConfig('mex');
cfg.TargetLang = 'C++';
cfg.DeepLearningConfig = coder.DeepLearningConfig('cudnn');
argstr = '{ones(4,1)}'; % "argstr = '{ones(5,1)}';" for my case
codegen('-config','cfg','evaluatePolicy','-args',argstr,'-report');

[伯儒 周]

Hi, Haonan Ding. Did you solve this problem? I met the same problem when I code a deep learning network follow the help document, I guess the problem may be resulted by the character vector input 'agenData.mat' and 'policy' but I cannot solve it just like you.

[伯儒 周]

I know how to solve the problem!

You should creat a new folder and the path can not contain any chinese symbal and the coder will work.

[XingZhou Mu]

Hello, did you solve this problem, I am also having the same problem

[XingZhou Mu]

Hello, did you solve this problem, I am also having the same problem

[Jie Li]

竟然是中文路径的问题！改成英文路径就OK了

Answer 1

[Paras Gupta]

Hello Haonan,

I understand that you're encountering the error "??? Expected a character vector."

This issue could arise if the name of the specified MAT-file or the absolute file path to the MAT-file contains non-ASCII characters, which are not supported by codegen. Please refer to the 'Limitations' section of the following documentation.

https://www.mathworks.com/help/gpucoder/ref/coder.loaddeeplearningnetwork.html

You can also refer to the below documentation for more information on character encoding in code generation:

https://www.mathworks.com/help/coder/ug/code-generation-for-characters.html

Hope this resolves the query.