Data type conversion in struct fields

Question

Ubaldo 2016-7-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/297068-data-type-conversion-in-struct-fields

评论： Guillaume 2016-7-25

Hi all,

I am running the following:

    Foo = 'MyModel/Foo';
blks = find_system(Foo,'BlockType','Constant');
TEMP_PAR = {''};
jj = 1;
for ii=1:length(blks);
    Blk_name = get_param(blks(ii),'Name');
    if ~strncmp(Blk_name,'Constant',8) && isempty(find(strcmp(Blk_name,TEMP_PAR),1))
        TEMP_PAR(jj,1) = Blk_name;
        TEMP_PAR(jj,2) = get_param(blks(ii),'Value');
        jj = jj+1;
    end
end
% create the DST struct
PAR_NAMES = TEMP_PAR(:,1);
PAR_VALUES = TEMP_PAR(:,2);
PAR.MySet = cell2struct(PAR_VALUES,PAR_NAMES,1);

But what I get in my struct is a set of parameters like

                           obs_c1: 'TempCoef(5)'
                           obs_c2: 'TempCoef(6)'
                              T0K: '273.15'
                             T0K1: '298'
                         Cp0_Cool: '3600'

Where the numerical array TempCoef is defined in the Workspace. What I would like is have the value of the fields as numbers, for example like this:

                           obs_c1: 27.2
                           obs_c2: -5.9
                              T0K: 273.15
                             T0K1: 298
                         Cp0_Cool: 3600

I tried str2double but it messes up the variables defined in the workspace. Any hint? Many thanks.

2 个评论
显示无隐藏无

Adam 2016-7-25

Without knowing anything about what find_system returns it is very hard to follow the flow of code that leads to you having these values for your struct in the first place.

str2double should work fine for the last 3 fields, though obviously not the first 2.

Guillaume 2016-7-25

@Adam, find_system is a simulink function. It returns a cell array of strings.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Azzi Abdelmalek 2016-7-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/297068-data-type-conversion-in-struct-fields#answer_229687

编辑：Azzi Abdelmalek 2016-7-25

在 MATLAB Online 中打开

This is not the best way to do but it works.

%------Example-----------------
TempCoef=rand(1,10)
v.obs_c1= 'TempCoef(5)'
v.obs_c2= 'TempCoef(6)'
v.T0K= '273.15'
v.T0K1= '298'
v.Cp0_Cool= '3600'
%-----------The code-------------------
name=fieldnames(v)
for k=1:numel(name)
  v.(name{k})=evalin('base', v.(name{k}))
end

Maybe you can avoid this situation by modifying your initial code

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。

Answer 2

Guillaume 2016-7-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/297068-data-type-conversion-in-struct-fields#answer_229688

在 MATLAB Online 中打开

I know nothing about simulink. Ideally, there would be a similar function to get_param that return the evaluated value of the parameter. Failing that, this is probably one of the rare cases where using eval makes sense:

TEMP_PAR(jj,2) = eval(get_param(blks(ii),'Value'))

Be aware that eval will execute whatever instruction is contained in the value of your parameter. So if one the values happens to be the string 'rm('C:\', 's')', it will happily reformat your hard disk.