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How can i save Data from a Database using a Gui and for-loops / How to access a functions workspace

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Mr Anderson
Mr Anderson 2015-9-15
回答： Mr Anderson 2015-9-16
Hi dear Matlab experts, I got a problem saving data downloaded from a database using a GUI im currently working on.
The situation is: The user selects the dates and the data-names(signals) he wants and the gui saves them into Timearray and Signalarray.
What I wanna do is after hitting the gui button, collecting the signal-data of each day chosen as variables and save them to a .mat file named after that day. So if Timearray contains '20-Feb-2015' and '21-Feb-2015' and Signalarray 'Signal1' and 'Signal2', i want one 20-feb-2015.mat, with var 'Signal1' and 'Signal2' and the same with the 21-feb-2015.mat.
My Problem is, i cant save the data received from the DB into the functions WS. From where I could save the via for-loop collected variables to a mat file.
The download of the data itself works fine for me.
function pushbutton49_Callback(hObject, eventdata, handles)
% hObject handle to pushbutton49 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
global TimeTableFinal;
Timearray = get(TimeTableFinal, 'Data');
Signalarray = get(handles.ChosenSignalsBox, 'String');
size_TA = size(Timearray);
size_SA = size(Signalarray);
for c1=1:size_TA(1)
BeginTicks = Timearray{c1,3};
EndTicks = Timearray{c1,4};
date_name = Timearray{c1,1};
splitDate = strsplit(date_name, {' '}); %cut date_name to create a valid filename
for c2=1:size_SA(1)
signalname = Signalarray{c2};
conn = database( *connection details* );
setdbprefs('DataReturnFormat','numeric');
sqlQuery = [*sql query string*];
curs = exec(conn, sqlQuery);
curs = fetch(curs);
signal_data = curs.Data;
assignin('base',signalname, signal_data);%renaming the the data containing variable 'signal_data' to its true name, provided by 'signalname'
% whos;
close(curs);%closing cursor and connection
close(conn);
% if c2==1
% save(splitDate{1}, signal_data)%first loop, create matfile with just recieved data
% else
% save(splitDate{1}, signal_data, '-append');%following loops, adding the just received data to already existing matfile
% end
%
end;
whos
% save(splitDate{1});
end;
At first i had the idea with
save(splitDate{1});
which doesnt work because ML then saves all variables and creates somekind of copy in the splitDate{1}-named matfile.
Then i tried
if c2==1
save(splitDate{1}, signalname)
else
save(splitDate{1}, signalname, '-append');
end
Wich should have saved the var 'signalname' to the specified matfile....but if I debug and enter a 'whos' its not even listed...so Matlab cant find it either.
Funny Thing is, the Data and the signals of the last round of the for-loop appears in my global workspace if i comment the saving parts.
Perfect would be a assign command, which assigns the variable to the functions workspace so i can use it directly.
What can i do? Thanks in advance!

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采纳的回答

Mr Anderson
Mr Anderson 2015-9-16
Whoever comes across the same problem, I kinda found a solution myself. Even though most experienced programers dont like eval(), its doing the job on my problem.
Solution:
In every of the inner for-loops I reassign the data received from the DB to a variable named like specified in my Signalarray.
So it looks something like this:
evalstring = [signalname ' = signal_data;'];
eval(evalstring);
this creates a Variable named after 'signalname' in the functions Workspace which later can be saved using the if-loop ive already implemented.

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