Data type conversion in struct fields

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Ubaldo
Ubaldo on 25 Jul 2016
Commented: Guillaume on 25 Jul 2016
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 Comments
Guillaume
Guillaume on 25 Jul 2016
@Adam, find_system is a simulink function. It returns a cell array of strings.

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Answers (2)

Azzi Abdelmalek
Azzi Abdelmalek on 25 Jul 2016
Edited: Azzi Abdelmalek on 25 Jul 2016
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

Guillaume
Guillaume on 25 Jul 2016
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.

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