Passing a structure from GUI to a function

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Chen Gafni
Chen Gafni 2014-11-29
评论： Image Analyst 2014-11-30
Hello, I created a GUI that generates a multi-field structure which is passed as an argument to a function (in a separated m file) selected by the user. It worked well for a while, but now every time I run the GUI, when the selected function is executed it fails to receive the intended structure. The structure looks fine before it is passed to the function, but when I check the function's varargin it says '[1x1 struct]', and obviously it doesn't preserve any of the fields of the original struct (when I try to access any such field I get an 'Attempt to reference field of non-structure array' error).
Bellow is the piece of code from the GUI (a callback function associated with a push button) that generates the structure (designParams) and calls the user-selected function (filename). The specific function I call has the header: function dataAnalysis (varargin)
Any idea what I'm doing wrong? Thanks,
Chen
% --- Executes on button press in runButton.
function runButton_Callback(hObject, eventdata, handles)
% hObject handle to runButton (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Get parameter values
designParams.titleFontSize = str2double(get (handles.titleFontSizeValue,'String'));
designParams.axesFontSize = str2double(get (handles.axesFontSizeValue,'String'));
designParams.tickFontSize = str2double(get (handles.tickFontSizeValue,'String'));
designParams.labelFontSize = str2double(get (handles.labelFontSizeValue,'String'));
designParams.fontType = get (handles.fontTypeValue,'String');
designParams.figureUnits = get (handles.figureUnitsValue,'String');
designParams.globalFigDim = get (handles.globalFigDim,'Value');
designParams.figureHeight = str2double(get (handles.figureHeightValue,'String'));
designParams.figureWidth = str2double(get (handles.figureWidthValue,'String'));
designParams.globalYScale = get (handles.globalYScale,'Value');
designParams.keepTitles = get (handles.keepTitles,'Value');
designParams.addDataLabel = get (handles.addDataLabels,'Value');
designParams.addLegend = get (handles.addLegend,'Value');
designParams.askFolder = get (handles.askFolder,'Value');
for colorInd=1:5
RColor= strcat('str2double(get (handles.RColor',num2str(colorInd),',''String''))');
GColor= strcat('str2double(get (handles.GColor',num2str(colorInd),',''String''))');
BColor= strcat('str2double(get (handles.BColor',num2str(colorInd),',''String''))');
designParams.colors(colorInd,1)=eval(RColor);
designParams.colors(colorInd,2)=eval(GColor);
designParams.colors(colorInd,3)=eval(BColor);
end
designParams.colors = designParams.colors/255;
% Open function for data analysis
filename = uigetfile ('*.m','Select the MATLAB code file');
[pathstr,name,ext] = fileparts(filename);
filename = str2func(name);
filename (designParams);

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回答（1 个）

Image Analyst
Image Analyst 2014-11-29
You forgot to show the code in the callback where you're actually calling dataAnalysis() and passing designParams to it.
If in dataAnalysis, it says that the input is a struct 1x1 that doesn't mean it has no fields. It will have fields. Just try this
a.f = 10;
whos a
See? So the fieldnames are probably not what you're using. Perhaps the capitalization is wrong. What does this say in dataAnalysis
filenames(varargin{1})
This will list all the field names of the first argument.
  2 个评论
Image Analyst
Image Analyst 2014-11-30
Chen's "Answer" moved here since it's not an "Answer" to the original question but a reply to me:
Thank you for the answer. Actually the code I submitted did include calling the destination function - I ask the user to select an m file and use its name as a function name:
% Open function for data analysis
filename = uigetfile ('*.m','Select the MATLAB code file');
[pathstr,name,ext] = fileparts(filename);
filename = str2func(name);
filename (designParams);
This code does run the desired function, but the structure itself is not passed as I expected. If I try to pass other types of arguments (e.g. double) to the function they are passed correctly. I typed whos designParams in the callback function and got:
Name Size Bytes Class Attributes
designParams 1x1 2892 struct
But when I typed whos varargin in dataAnalysis I got:
Name Size Bytes Class Attributes
varargin 1x1 3004 cell
If it preserved the desired information I don't know how to access it. Any advice?
Image Analyst
Image Analyst 2014-11-30
Well of course varargin is a cell - we know that. You need to extract the variable from the varargin cell array first. What does this say in dataAnalysis:
fprintf('Number of arguments = %d\n', nargin);
dp = varargin{1} % Extract designParams from the first cell
whos dp % Show infomation about it.

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