Plots in one graph GUI evalin

Hello! I have a listbox and I would like that when I select several inputs in the listbox and click a button called "plot", the axes plots the variables I have selected. The variables could be "var1,2,3,4" but not var_p because it's fixed, it's the time. This is my code:

function [var_p,var1_p,var2_p,var3_p,var4_p] = get_var_names1(handles)
% Returns the names of the variables to plot_button1
global index_selected
list_entries = get(handles.listbox1,'String');
index_selected = get(handles.listbox1,'Value');
var_p = 'Temps';
var1_p =[]; 
var2_p =[]; 
var3_p =[]; 
var4_p =[]; 

   if isempty(index_selected)
       errordlg('You must select one variable','Incorrect Selection','modal')
   else
      %var = list_entries{index_selected(1)};
      var1_p = list_entries{index_selected(1)};
      var2_p = list_entries{index_selected(2)};
      var3_p = list_entries{index_selected(3)};
      var4_p = list_entries{index_selected(4)};
  end 

function plot_button1_Callback(hObject, eventdata, handles)
 global index_selected
[x,y1,y2,y3,y4] = get_var_names1(handles);

if isempty(x) && isempty(y1)
    return
end
axes(handles.axes1); 
figure(gcf)

try  
    if index_selected==1 && index_selected==2 && index_selected==3 && index_selected==4 
    evalin('base',['plot(',x,',',y1,',',x,',',y2,',',x,',',y3,',',x,',',y4,')'])

      datetick('x', 31, 'keepticks','keeplimits' );          %'keepticks'  'keeplimits'
      xlabel('Date')
      xticklabel_rotate;   % calls file (available from matlab file exchange) that allows to display the label's ticks with a rotation of 45°

catch ex
    errordlg(...
      ex.getReport('basic'),'Error generating linear plot','modal')
end

This code kinda works but it means I have to do all the combinaisons like:

if index_selected==1
evalin('base',['plot(',x,',',y1,')]
if index_selected==1 && index_selected==2
evalin('base',['plot(',x,',',y1,',',x,',',y2,')])

ect... i have tried:

     if index_selected==1  
      evalin('base',['plot(',x,',',y1,')'])
      elseif index_selected==2  
      hold(handles.axes1)
          evalin('base',['plot(',x,',',y2,')'])
      elseif index_selected==3  
          evalin('base',['plot(',x,',',y3,')'])
      elseif index_selected==4
          evalin('base',['plot(',x,',',y4,')'])
          hold off
      end

but it doesnt work, gives me the error: Attempted to access index_selected(2); index out of bounds because numel(index_selected)=1.

Error in desk>get_var_names1 (line 348) var2_p = list_entries{index_selected(2)};

Error in desk>plot_button1_Callback (line 355) [x,y1,y2,y3,y4] = get_var_names1(handles);

I'm using R2013a. Can anyone help? Thank you!

Answer 1

[Dimitris Iliou]

If understand your question correctly, you are trying to plot the choices that are selected in a list-box.

The error that you are getting:

Attempted to access index_selected(2); index out of bounds because numel(index_selected)=1.

is because the length(index_selected) will be equal to the number of choices you have picked on the list-box. For example, if you only choose choices 3,4 the index_selected should be:

index_selected = 
    3 4 
length(index_selected) =
   2

and that is why you get the error.

So instead of using the code:

if isempty(index_selected)
     errordlg('You must select one variable','Incorrect Selection','modal')
 else
    %var = list_entries{index_selected(1)};
    var1_p = list_entries{index_selected(1)};
    var2_p = list_entries{index_selected(2)};
    var3_p = list_entries{index_selected(3)};
    var4_p = list_entries{index_selected(4)};
end

You can modify it as:

   if isempty(index_selected)
       errordlg('You must select one variable','Incorrect Selection','modal')
   else
      for i=1:length(index_selected)
        var_p = [var_p list_entries{index_selected(i)}];
      end
  end

The

   var_p = [var_p list_entries{index_selected(i)}];

takes advantage of the fact that if you have a 5x3 matrix A, and you plot(A), then the figure will have 3 lines, each having 5 points.

You can verify that on your own by running the following script:

C = rand(5,1);
plot(C);
hold on
for i=1:3
  D = rand(5,1);
  C = [C D];
  pause(1)
  plot(C)
end

In every iteration, a new column is concatenated to the matrix (in your case it would be a different list-box choice).

So, instead of using eval and try to identify the indices, I would try using this notation to create a matrix that contains all the current choices, and then plot that matrix.