Function to create struct with parameters

Question

Felix Müller 2021-4-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/813360-function-to-create-struct-with-parameters

评论： Felix Müller 2021-4-27

Currently I have a function with settings/parameters for my program, where all parameters are written into a struct like "inp.month = 7;" so that I can pass the struct "inp" to functions afterwards. Is it possible to have all the assignments in the function without the struct, eg "month = 7;" and at the end somehow get 'all variables in this function' into the struct "inp". Something like "inp = <gather all variables assigned in this function>", and then have the struct be the output. It would add readability in my opinion and also I thought this to be easy, but didn't find a good solution yet and thought I'd ask here.

Cheers

Felix

5 个评论
显示 3更早的评论隐藏 3更早的评论

Bruno Luong 2021-4-27

This request is interesting only for lazy programmers who wants to make a quick and dirty code.

Just create a struct with the list of variables that you control explicitly.

Felix Müller 2021-4-27

Well, that might not be so obvious before thinking about it, eh?

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Jeff Miller 2021-4-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/813360-function-to-create-struct-with-parameters#answer_685520

在 MATLAB Online 中打开

Maybe you would like something like this?

month = 1;
year = 1951;
day = 11;
inp = CreateStruct(month,day,year)
function outstruc = CreateStruct(varargin)
    % Create a structure with the input variables as fields.
    outstruc = struct;
    for iField=1:numel(varargin)
        sfName = inputname(iField);
        outstruc.(sfName) = varargin{iField};
    end
end

2 个评论
显示无隐藏无

Felix Müller 2021-4-27

Thanks, that does look interesting. Do you think there are any drawbacks or weird errors that could pop up while using this?

Stephen23 2021-4-27

编辑：Stephen23 2021-4-27

"Do you think there are any drawbacks...?"

Slower code: "Avoid functions that query the state of MATLAB such as inputname, which, whos, exist(var), and dbstack. Run-time introspection is computationally expensive."

source: https://www.mathworks.com/help/matlab/matlab_prog/techniques-for-improving-performance.html

请先登录，再进行评论。

Answer 2

Walter Roberson 2021-4-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/813360-function-to-create-struct-with-parameters#answer_684845

在 MATLAB Online 中打开

The following code is not recommended.. but it should work.

ZZ_filename = [tempname '.mat'];
save(ZZ_filename, '-struct', '-regexp', '^[^Z]', '^Z[^Z]');
inp = load(ZZ_filename);
delete(ZZ_filename);

If you already have variable names that begin with 'ZZ' then this code would have to be modified.

The purpose of the -regexp is to allow saving all of the variables except the over-head variable ZZ_filename .

3 个评论
显示 1更早的评论隐藏 1更早的评论

Walter Roberson 2021-4-26

Then you will need to write code that uses dynamic variable naming, which is not at all recommended.

http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Hint: who() returns names of variables.

Felix Müller 2021-4-26

Okay, thanks! I thought it might work without fiddling with the assignment of variables myself (eg with a function written exactly for this), but it might not.

请先登录，再进行评论。

Answer 3

Bruno Luong 2021-4-27

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/813360-function-to-create-struct-with-parameters#answer_685815

在 MATLAB Online 中打开

s = buildparams()
s = struct with fields:
    a: 1
    b: 2
function s = buildparams()
a = 1;
b = 2;
s = gathervars();
end
function s = gathervars()
vars = evalin('caller', 'whos');
for k=1:length(vars)
    name = vars(k).name;
    s.(name) =  evalin('caller', name);
end
end