How to filter a signal(s) open in a UIAXES in matlab app designer?

Hi All

I have a listbox from which I choose some signal names and plot them on my UIAXES. now wanted to make a filter button. how could I transfer those signals to the filtering button ?

maybe assuming I have 3 signals already plotted

[Ameer Hamza]

Can you elaborate what the filtering button does?

[farzad]

well, as you remember, I click on some filenames and I also have put a hold on button that I can hold the plots when being plotted on the UIAXES. once this is done and I have 3 plots present in the UIAXES, I want to press the filter button, with some defined variables let's say this one , get the plotted signals' variables : x-t and (then filter the x to y)

and plot the filtered signal over the same UIAXES

Answer 1

[Ameer Hamza]

Please check the attached file. It gives a general idea of how to apply a filter on the current line plotted on a UIAxes. You can modify it according to your requirements.

[farzad]

Thank you very much ! this is great !!! only one thing, I wanted to keep the unfiltered together with the filtered values to compare and be able to save the filtered values to Excel later. How is that possible ? and also how do I grab the name of each unfiltered data I am filtering to add that to the filtered data plot in the legend ?

I did

                fdata(i) = filter(b, a, app.UIAxes.Children(i).YData);
                tem(i)= app.UIAxes.Children(i).XData;
                plot(app.UIAxes,tem,fdata(i));

and I get an error : Subscripted assignment dimension mismatch.. and if I don't put an index, it gives the error index dimensions mismatch

[Ameer Hamza]

Please check the updated app. I have shown how to use tag property to check which lines are needed to filter and which should be left unchanged.

[farzad]

Thank you so much, what does

if strcmp(app.UIAxes.Children(i).Tag, 'f')

do ?

I mean why do we use tag ?

I needed to add another pushbutton to write the filtered Y (together with time columns) to excel files. but now I see that I can not just assign

app.fity= app.UIAXes.Children(i).DataY

or not ?

[Ameer Hamza]

farzad, I gave the tag of 'f' and 'uf' to lines to identify whether to filter it or not. There are a total of 6 lines. Without tags, we cannot identify, which one of them needed to be filtered.

Similar to the plot, you can use the tag property to se which children are filtered and save their values.

[farzad]

thank you very much. It just confused me a little bit. actually I had not noted the lines that define the tags in plotting.

but there is a question for me now. these lines are not under any for condition, and just repeat the same thing with the same name but different tag. so I don't understand how it plots both filtered and unfiltered over eachother.

[Ameer Hamza]

If you see in the ListBoxValueChanged, it plots two lines with same x and y

p = plot(app.UIAxes, x, y);
p.Tag = 'uf'; % unfiltered
p = plot(app.UIAxes, x, y);
p.Tag = 'f'; % filtered

So these two lines overlap. When you click the filter button, one of these lines gets filtered, and the other remains the same. I found that this is the easiest way to draw both filtered and unfiltered lines.

[farzad]

Thank you so much for your super amazing help !

ok now I wanted to remove the original plot after overlaying ( therefore I could have both of the method included in my code)

so I made another button to remove the original plot, but there is a logic failure from my side. since if I loop and inside the loop delete a UIAxes.children(I), I will have index exceeds matrix dimensions. any idea on how to resolve it ?

[Ameer Hamza]

Start the loop in reverse order

for i=numel(app.UIAxes.children):-1:1

[farzad]

amazing solution !!!

[farzad]

dear Ameer! I did this , following your instructions, but I did the hold button a little bit differently. I have a problem : when I hold the plots and then delete the original plots, the last plot label dispears !

and when I uncheck hold plots, and then filter, it does not hold the original plot

then I wanted to save app.fity and app.fitt in savefiltered button function, but I am not sure if I can use them directly

        function HoldPlotsCheckBoxValueChanged(app, event)
            value = app.HoldPlotsCheckBox.Value;
            % on pressing hold button, all previous lines will be deleted
            delete(app.UIAxes.Children);
%             if value==1
%                 hold(app.UIAxes);
%             else
%                 hold(app.UIAxes, 'off');
%             end
            
        end

        % Value changed function: FilesListBox
        function FilesListBoxValueChanged(app, event)
            
            switch app.HoldPlotsCheckBox.Value
               case 0
                   cla(app.UIAxes)
                   drawnow;
    %             FocusUIFigure(app.UIFigure)
%                   app.UIFigure.Visible = 'off';
%                   app.UIFigure.Visible = 'on';
                   filename = app.FilesListBox.Value;
                   data = xlsread(filename);
                   
                   p=plot(app.UIAxes, data(:,1), data(:,2));
                   p.Tag = 'uf'; % unfiltered
                   legend(app.UIAxes,filename);
                   p=plot(app.UIAxes, data(:,1), data(:,2));
                   p.Tag = 'f'; % filtered
                   legend(app.UIAxes,filename);
              
               
               case 1
                   hold(app.UIAxes);
                   
                   
                   drawnow;
%                    FocusUIFigure(app.UIFigure)
%                    app.UIFigure.Visible = 'off';
%                    app.UIFigure.Visible = 'on';
                   filename = app.FilesListBox.Value;
                   app.names{end+1} = filename;
                   data = xlsread(filename);
                   
                   p=plot(app.UIAxes, data(:,1), data(:,2));
                   p.Tag = 'uf'; % unfiltered 
                   legend(app.UIAxes,app.names);
                   p=plot(app.UIAxes, data(:,1), data(:,2));
                   p.Tag = 'f'; % filtered
%                    plots(end+1)=pl;
                   legend(app.UIAxes,app.names);
                   
                   hold(app.UIAxes);
                   
                   
                  
           end
            
        end

        % Button pushed function: UpdatefilesButton
        function UpdatefilesButtonPushed(app, event)
            
            files = dir('*.xlsx');
            app.FilesListBox.Items = {files.name};
        end

        % Button pushed function: ClearPlotButton
        function ClearPlotButtonPushed(app, event)
            app.names={};
            cla(app.UIAxes)
        end

        % Button pushed function: FilterButton
        function FilterButtonPushed(app, event)
            windowSize = app.window; 
            b = (1/windowSize)*ones(1,windowSize);
            a = app.aval;
            for i=1:numel(app.UIAxes.Children)
                if strcmp(app.UIAxes.Children(i).Tag, 'f')
                    app.UIAxes.Children(i).YData = filter(b, a, app.UIAxes.Children(i).YData);
                    app.fitY= app.UIAxes.Children(i).YData;
                    app.fitt= app.UIAxes.Children(i).XData;
                end
            end
        end

     
        % Button pushed function: SaveFilteredButton
        function SaveFilteredButtonPushed(app, event)
            
        end

        % Button pushed function: RemoveOriginalButton
        function RemoveOriginalButtonPushed(app, event)
            for i=numel(app.UIAxes.Children):-1:1
                if strcmp(app.UIAxes.Children(i).Tag, 'uf')
                    delete(app.UIAxes.Children(i));
                    
                end
            end

[farzad]

I also tried set(app.UIAxes.Children(i),'visible','off') , but then the legend colors lose their synchronization with the actual filtered plots

and also, it seems that plotting two plots, causes the legend color lose harmony with the visible ones. how could I resolve it ?

[farzad]

dear Ameer, now the biggest problem is that if I have 6 plots in UIAxes, how to save them in the right order to one file ?

[Ameer Hamza]

farzad, for the legend color issue, you will need to specify the colors in the plot statement explicitly. You can create a property named colors and assign it RGB values of several colors. You can also create a property named counter to keep track of how many colors are used. Something like this

p=plot(app.UIAxes, data(:,1), data(:,2), 'Color', obj.colors(obj.counter,:)); % define the color value
p.Tag = 'uf'; % unfiltered 
legend(app.UIAxes,app.names);
p=plot(app.UIAxes, data(:,1), data(:,2), 'Color', obj.colors(obj.counter,:)); % define the color value
p.Tag = 'f'; % filtered
obj.counter = obj.counter + 1;

This will help in keeping track of colors.

For the order of UIAxes, you created them initially, so you know their handles and in which order they are placed. From that information, you should be able to know their order. Somehow, even if that information cannot be used, you can check the position property of uiaxes object to find out their order. Axes with lower x positions will be on the left as compared to any axis on the right.

[farzad]

dear Ameer ! I was trying to write the data while pressing the button filter, but I was not successful, I do not get the variable fildat as a 2 column matrix to write it to excel but a 1D array. How to make it a 2 column matrix ?

function FilterButtonPushed(app, event)
            
            windowSize = app.window; 
            b = (1/windowSize)*ones(1,windowSize);
            a = app.aval;
            for i=1:numel(app.UIAxes.Children)
                if strcmp(app.UIAxes.Children(i).Tag, 'uf')
                    app.UIAxes.Children(i).YData = filtfilt(b, a, app.UIAxes.Children(i).YData);
                    app.fitY= app.UIAxes.Children(i).YData;
                    app.fitt= app.UIAxes.Children(i).XData;
                    name1=app.names{i};
                    [pathstr, name2, ext] = fileparts(name1)
                    name=strcat(name2,'filtered')
                    fildat=[app.fitt,app.fitY];
                    size(app.fitt)
                    size(fildat)
                    xlswrite(name,fildat,1);
                end
            end

[Ameer Hamza]

Can you add a breakpoint at this line to see what is the dimensions of fildat? From the code it seems it should have two columns.

[farzad]

I know its dimensions.

If app.fitt is 1x10, fidata is 1x20

[Ameer Hamza]

Ok, i get it. Those are row vectors. Use transpose

fildat=[app.fitt.',app.fitY.'];

[farzad]

Excellent ! There is a new problem : I wanted to append each Children.Ydata to one row of app.fitY, but I can not subscribe it correctly and I get the error :

Subscripted assignment dimension mismatch.

if I swap to app.fitY(:,i) I get the error :

Assignment has more non-singleton rhs dimensions than non-singleton subscripts 

        function FilterButtonPushed(app, event)
            
            windowSize = app.window; 
            b = (1/windowSize)*ones(1,windowSize);
            a = app.aval;
            for i=1:numel(app.UIAxes.Children)
                if strcmp(app.UIAxes.Children(i).Tag, 'uf')
                    app.UIAxes.Children(i).YData = filtfilt(b, a, app.UIAxes.Children(i).YData);
                    app.fitY(i,:)= app.UIAxes.Children(i).YData;
                    app.fitt(i,:)= app.UIAxes.Children(i).XData;
                    
                end
            end
            

[Ameer Hamza]

Use something like this

windowSize = app.window; 
b = (1/windowSize)*ones(1,windowSize);
a = app.aval;
app.fitY = [];
app.fitt = [];
for i=1:numel(app.UIAxes.Children)
    if strcmp(app.UIAxes.Children(i).Tag, 'uf')
        app.UIAxes.Children(i).YData = filtfilt(b, a, app.UIAxes.Children(i).YData);
        app.fitY = [app.fitY app.UIAxes.Children(i).YData];
        app.fitt = [app.fitt app.UIAxes.Children(i).XData];
    end
end

[farzad]

no if I have more than one plot, this will save only the last filtered plot info to the 2 variables fitY and fitt. They should take each array , relating to each plot in each of their rows, something I did not succeed to do

[Ameer Hamza]

This will not just save last plot, it will save all the plots inside the for loop. It append them as a single row. If you want to save each plot in a seperate row then change it to

app.fitY = [app.fitY; app.UIAxes.Children(i).YData];
app.fitt = [app.fitt; app.UIAxes.Children(i).XData];

But this require that all plots have same number of points.

[farzad]

Thank you so much ! It worked

[farzad]

a problem :

I always have difficulty in getting the parameter from another Editfield or button and use it in another in app designer, it sometimes works sometimes not.

For example , I wanted to plot from a file that contains more columns , so plot all other columns vs the first column that is supposed to be the horizontal axis. in this case, I should name each plot and I should take this names from the user plus the filename I hit on the listbox. so I created Editfield and wrote a default value X in it.

then I created a public property xedit=' ' , and then under editfield function :

% Value changed function: EditField
        function EditFieldValueChanged(app, event)
            app.xedit = app.EditField.Value;
            app.yedit = app.EditField.Value;
            app.zedit = app.EditField.Value;
            
        end

but this did not work, I mean did I wrongly use Value changed function and I had to use value changing function ? or what would be the error ? app.xedit =' ' always in the code

[Ameer Hamza]

What do you mean by did not work. Did the value does not get assigned to varaibles. Add a breakpoint at this line to check what is teh value of app.EditField.Value.

[farzad]

I mean that the code does not get the default value 'X' from the edit field to strcat it with the filename.

there was Editfieldvaluechanged and I used that not the value changing one.

[farzad]

app.EditField.Value gives

ans =

0×0 empty char array

[farzad]

I also have a numeric edit field and the code gets that value without problem, but with the same method, the text input for these edit field does not work and they remain empty char

[Ameer Hamza]

I am not sure. app.EditField.Value should return the text inside the edit field as a char array. Make sure that the callback function is assigned to the correct edit field.

[farzad]

It resolved by opening and closing matlab, sometimes adding new variables are not uploaded to matlab base.

by the way , one doubt : If I have to choose a file in the listbox, I should have more than 1 file, at least two, to be able to hover from one over the other. what if I have only one file in the folder ?

[Ameer Hamza]

Can you show the picture of the listbox and what is the issue with single file?

[farzad]

Sure , here is the listbox. If I have only one single file, I can not hover with mouse over it and click it, despite it is even highlighted , nothing can be plotted

[Ameer Hamza]

Yes, that seems to be an issue. MATLAB only generates a callback when the value is changed. What about adding a dummy field which user can click when when no file is selected.

[farzad]

What is that dummy field and how is it created ? I have no Idea

[Ameer Hamza]

By dummy field, I mean, just add an additional item in the list, for example "none", after all the file names. This will allow user to select "none" and then reselect the filename.

[farzad]

Thank you , how do I create that ?

[farzad]

Another problem : new : Using the plot children, I tried to plot the acceleration, but this plots nothing , why ?

app.Yd = [];
            app.Xt = [];
            for i=1:numel(app.UIAxes.Children)
%                 if strcmp(app.UIAxes.Children(i).Tag, 'uf1')
                i;
                app.Yd = [app.Yd; app.UIAxes.Children(i).YData];
                app.Xt = [app.Xt; app.UIAxes.Children(i).XData];
%                 end
            end
            tf= app.Xt.';  %satri be sotuni
            yf=app.Yd.';
            
            dyf=gradient(yf)./gradient(tf);
            ddyf=gradient(dyf)./gradient(tf);
            
            cla(app.UIAxes)
            drawnow;
            
            pa1=plot(app.UIAxes, tf(:,1), ddyf(:,1))
            pa1.Tag = 'acc1'; % unfiltered          
            hold(app.UIAxes,'on');

[farzad]

pa1has data but nothing is drawn

pa1 = 

  Line with properties:

              Color: [0 0.4470 0.7410]
          LineStyle: '-'
          LineWidth: 0.5000
             Marker: 'none'
         MarkerSize: 6
    MarkerFaceColor: 'none'
              XData: [1×15360 double]
              YData: [1×15360 double]
              ZData: [1×0 double]