evalin data dictionary design data unable to use parameters on rhs of expression

Question

Adam Jaslikowski 2020-8-25

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/584372-evalin-data-dictionary-design-data-unable-to-use-parameters-on-rhs-of-expression

评论： Adam Jaslikowski 2020-8-28

I'm trying to write a MATLAB script that can perform pre-processing computations on a data dictionary prior to Simulink running. I've been trying to write a script that is called from the 'evalin' interface with the Dictionary design data section as the first input and my script as the second:

evalin(section,'my_script');

Assume the dictionary already has parameters x and y with some arbitry values

if my_script.m has:

x=1;
y=2;

There's no problem. If I modify my_script.m to:

y=x+1;

There is an error when calling evalin:

"Could not evaluate 'my_script' in data dictionary

Caused by:

Error occurred."

After further testing, it doesn't seem like I can use an existing parameter anywhere on the rhs of an equation. Is this correct?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Mohith Kulkarni 2020-8-28

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/584372-evalin-data-dictionary-design-data-unable-to-use-parameters-on-rhs-of-expression#answer_486290

The "evalin" function for data dictionary section does not support the expressions where the value contains data entries as of now. But I have brought this issue to the concerned people and it might be considered in any future release.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Adam Jaslikowski 2020-8-28

Thank you

请先登录，再进行评论。

Answer 2

stozaki 2020-8-28

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/584372-evalin-data-dictionary-design-data-unable-to-use-parameters-on-rhs-of-expression#answer_486329

编辑：stozaki 2020-8-28

在 MATLAB Online 中打开

The "evalin" function for data dictionary section does not support the expressions.

The workaround can be replaced by the following formula.

Simulink.data.evalinGlobal(modenName,expression)

Simulink.data.evalinGlobal

For example, how about preparing a wrapper function like the following?

function [Object] = evalinCustomWrap (modelName,varStr)
modelVar = verLessThan('Simulink','8.5');
if ~modelVar
    % If the target model is using a MATLAB release supported by .sldd
    try
        Object = Simulink.data.evalinGlobal(modelName,varStr);
    catch
        Object = [];
    end
else
    % If the target is using a MATLAB release that does not support sldd
    % Only evalin can be used
    try
        Object = evalin('base',varStr);
    catch
        Object = [];
    end
end
end

Regards,

stozaki

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Adam Jaslikowski 2020-8-28

I'm experiencing the same issue when attempting to use Simulink.data.evalinGlobal. This is very dissappointing. I just learned of data dictionaries and they seem like very useful tools; however, my use case requires a great deal of pre-processing on the data prior to use by the Simulink model and it seems like that is just not supported (other than doing a lot of calls to "getEntry" and "getValue"). Thank you for trying to help,

Adam

请先登录，再进行评论。