Adding legend of different names in a plot generated by a for loop

I am performing Data Analysis for calenderic tests in various batteries. The various cell names are stored in M5BAT.CellList folder. I plot the graph for two different temperature ranges as shown below. I want to include the legend as the cell name or number chosen for different temperatures for every graph. close all clear all load('M5BAT_analysis_all.mat') plottype = 3;

 %General constants    
    %MAXCYC = 30000;
    MAXSOH = 103;
    %MINSOH = 95;
    MINSOH = 10;
    Colour = colormap(jet(8));
    Temp = [25 50];
    CyclingDepth = [100 50 10 2];
    CurrentRate = [0.75 1];

    % Constants for different calendric test options
    Cal.Num = [1:9];
    Cal.Temp = [50 50 25 25 50 50 50 50 50];
    Cal.SoC = [10 50 50 50 30 50 50 80 100];
    % Set up a List where the direct pointers to all elements are stored
    % for calendric Cells
    for i=1:size(Cal.Num, 2)
        for j=1:size(M5BAT.CellList, 2)
            if M5BAT.CellList(j).Number == Cal.Num(i)
                Cal.Index(i) = j; % Cal.Index = 1 2 3 4 5 6 7 8 9
            end
        end
    end

     for i=1:2 % it loops for different temperatures, 1 for 25 degree and for both 25 and 50 degree Celsius
         % Go Through the two differnet temperatures
                Index = find(Cal.Temp == Temp(i));
                subplot(1, 3, i); % Definition of the subplot (three subplot in this case)

                for j=1:size(Index, 2)               
                    %sort dates                                    
                    d = 0; %initiation
                    for d=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2)% gives the number of cells corresponding to 
                        % that particular temperature

                        DateVec(d) = M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Sort; %converts date and time to vector
                        CrealVec(d)= M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Creal10;
                        %DateVec_1(d) = M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Sort;
                        %CrealVec_1(d)= M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Creal10;
                        %DateVec_2(d) = M5BAT.CellList(Cal.Index(Index(j-2))).ResultList(d).Sort;
                        %CrealVec_2(d)= M5BAT.CellList(Cal.Index(Index(j-2))).ResultList(d).Creal10;

                    end

                    %calculate days in between checkups and capacity
                    for k=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2)                                      
                        XValue(k) = DateVec(k) - DateVec(1); %storage days
                        YValue(k) = CrealVec(k) / CrealVec(1) * 100; %capacity
                    end

                    if d > 0                       
                    plot(XValue , YValue, '-xb', 'Color', Colour(ceil(j),:), 'LineWidth', 2, 'MarkerSize', 8);

                    hold on;
                 %   legendInfo {j}= ['Cell.number='{M5BAT.CellList(j).result}];
                  %  legend(legendInfo));

                    clear XValue YValue;

                   end
                end

                axis([0 150 85 103]);
                grid on;
                xlabel('Storage Time / in Days');
                ylabel('Capacity / in %');
               % legend(['Cell.number = ' num2str(M5BAT.CellList(Index(j)))]);
                title(['Ageing at ' num2str(Temp(i)) '°C']);  

                legendInfo{j}=(['Cell.name = ' num2str(j)]);
                legend(legendInfo);
               % for p=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2);
                %    legendInfo{p}= ['Cell.number = ', {p}];
                 %   legend(legendInfo)
                %end

            end

I tried using legendInfo but it is not working. I will be grateful for any help regarding this. I have attached the plot for this code. I want to include the name of different cells considered for that particular temperature. Please help me about how i could do that. Thanks in advance!

Answer 1

[Benjamin Kraus]

It isn't clear what you mean by "various cell names are stored in M5BAT.CellList folder", but it looks like you are trying to create a set of names for the various lines in your plot.

Here is (some of) the code you tried:

for p=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2);
  legendInfo{p}= ['Cell.number = ', {p}];
  legend(legendInfo)
end

I see at least two issues with that code:

1. You are trying to concatenate the number ('p') to a string. You can do that using 'num2str' or 'sprintf':

legendInfo{p} = ['Cell.number = ', num2str(p)];

or

legendInfo{p} = sprintf('Cell.number = %d', p);

2. You want to make only a single call to the legend command that includes all the names:

for p=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2);
  names{p} = ['Cell.number = ', num2str(p)];
end
legend(names);

For example, here is sample code using some simple data:

hold on
for p = 1:5;
  names{p} = ['Line Number ' num2str(p)];
  plot(1:10,(1:10)+p)
end
legend(names)

An alternative approach that may work for you is to use the 'DisplayName' property when calling 'plot':

hold on
for p = 1:5;
  name = ['Line Number ' num2str(p)];
  plot(1:10,(1:10)+p, 'DisplayName', name)
end
legend show

Both sets of code will produce the same image:

[Tejaswini Ramesh]

Thank you so much for the help! I incorporated this in my code but it is not working completely for me. I perform the battery tests for two different temperatures-->i at each different temperatures, there are different cells (whose names ans details are stored in folder called cell list) under test, that gives j. therefore i have to plot the different cell names in the legend. Please guide me. Here is the code: close all clear all load('M5BAT_analysis_all.mat') plottype = 3;

 %General constants    
    %MAXCYC = 30000;
    MAXSOH = 103;
    %MINSOH = 95;
    MINSOH = 10;
    Colour = colormap(jet(8));
    Temp = [25 50];
    CyclingDepth = [100 50 10 2];
    CurrentRate = [0.75 1];

    % Constants for different calendric test options
    Cal.Num = [1:1:9];
    Cal.Temp = [50 50 25 25 50 50 50 50 50];
    Cal.SoC = [10 50 50 50 30 50 50 80 100];
    % Set up a List where the direct pointers to all elements are stored
    % for calendric Cells
    for i=1:size(Cal.Num, 2)
        for j=1:size(M5BAT.CellList, 2)
            if M5BAT.CellList(j).Number == Cal.Num(i)
                Cal.Index(i) = j; % Cal.Index = 1 2 3 4 5 6 7 8 9
            end
        end
    end

     for i=1:2 % Go Through the two differnet temperatures
                Index = find(Cal.Temp == Temp(i));
                subplot(1, 3, i); % Definition of the subplot

                for j=1:size(Index, 2)               
                    %sort dates                                    
                    d = 0
                    for d=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2)
                        d
                        DateVec(d) = M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Sort;
                        CrealVec(d)= M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Creal10;
                        %DateVec_1(d) = M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Sort;
                        %CrealVec_1(d)= M5BAT.CellList(Cal.Index(Index(j))).ResultList(d).Creal10;
                        %DateVec_2(d) = M5BAT.CellList(Cal.Index(Index(j-2))).ResultList(d).Sort;
                        %CrealVec_2(d)= M5BAT.CellList(Cal.Index(Index(j-2))).ResultList(d).Creal10;

                    end

                    %calculate days in between checkups and capacity
                    for k=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2)                                      
                        XValue(k) = DateVec(k) - DateVec(1);
                        YValue(k) = CrealVec(k) / CrealVec(1) * 100;
                    end

                     for p = 1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2);
                      %  plot(XValue , YValue, '-xb', 'Color', Colour(ceil(j/1),:), 'LineWidth', 2, 'MarkerSize', 8);
                   names{p} = ['Cell Number ' num2str(p)];

                     end
                   legend((names),'Location','Southeast');

                    if d > 0                       
                    plot(XValue , YValue, '-xb', 'Color', Colour(ceil(j/1),:), 'LineWidth', 2, 'MarkerSize', 8);
                   % names{p} = ['Cell Number ' num2str(M5BAT.CellList(Cal.Index(Index(j))))];
                    hold on;
                    clear XValue YValue;
                   % for p=1:size(M5BAT.CellList(Cal.Index(Index(j))).ResultList,2);
                  %  names{p} = ['Cell.number = ', num2str(p)];
                  %  end
                  %  legend((names),'Location','Southeast');
                  %  hold on

                   legend((names),'Location','Southeast');

                    end
                end
                axis([0 150 85 103]);
                grid on;
                xlabel('Storage Time / Days');
                ylabel('Capacity / %');

                title(['Ageing at ' num2str(Temp(i)) '°C']);                
            end

[Tejaswini Ramesh]

It worked :) Thank you very much for your support :)