Legend of subplot duplicates entry after for loop

I have this code for some plots that are created in a for loop. this "Real_Time_Plots" function gets called for every time step of the simulation. The problem i am having is that as it is every time the function gets called, the legend of the subplot gets duplicated (Example: First function call the legend has the following entries: Pr1, Pr2, Pr3. On the Second call the legend is double the length with following entries: Pr1, Pr2, Pr3, Pr1, Pr2, Pr3 eventho no new lines were added to the plot ). Am i writing the "hold on's" and "hold off's" at the wrong place?

function Real_Time_Plots(System_Handle, TimeStep_Count )

%Subplots get created

if (isfield(System_Handle.Cache_DynamicVariables,'f1'))

elseif ~(isfield(System_Handle.Cache_DynamicVariables,'f1'))

System_Handle.Cache_DynamicVariables.f1 = figure(1);

ax1 = subplot( 2,3,1 );

ax2 = subplot( 2,3,2 );

ax3 = subplot( 2,3,3 );

ax4 = subplot( 2,3,4 );

ax5 = subplot( 2,3,5 );

ax6 = subplot( 2,3,6 );

System_Handle.Cache_DynamicVariables.child_handles = get(System_Handle.Cache_DynamicVariables.f1,'Children');

else

end

%Name and color array initialization

precipitates = size(System_Handle.Precipitates, 1);

names = cell(precipitates,1);

cc = jet(precipitates);

for i=1:1:precipitates

names{i}=strcat('Pr', num2str(i));

end

%First Subplot

xlim(System_Handle.Cache_DynamicVariables.child_handles(1,1), [0, t_end]);

xlabel(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'time in s' );

ylabel(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'mean radius in m' );

set(System_Handle.Cache_DynamicVariables.child_handles(1,1),'XScale','log');

set(System_Handle.Cache_DynamicVariables.child_handles(1,1),'YScale','log');

set(System_Handle.Cache_DynamicVariables.child_handles(1,1),'FontSize',16);

hold(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'on' );

for i=1:1:precipitates

if System_Handle.Precipitates{i, 1}.Physical_Properties.IsClusterPhaseType

plot(System_Handle.Cache_DynamicVariables.child_handles(1,1), ...

... Time(1:TimeStep_Count,1), MeanRadius.DataTable(1:TimeStep_Count,3 ), 'DisplayName', names{i} , 'color', cc(i,:) , 'LineStyle', '-');

end

end

legend(System_Handle.Cache_DynamicVariables.child_handles(1,1),'Location','best');

hold(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'off' );

%Code for the rest of subplots

drawnow

end

Answer 1

[Walter Roberson]

setting xlim and fontsize and the other items do not cla (clear axes).

You then hold on, draw, hold off.

Next cycle you re-do setting the limits and so on, none of which removes anything from the axes. You then hold on... which tells matlab not to remove any of the lines from the previous cycle. You add more lines, hold off..

Using hold off does not erase anything: it just sets the conditions so that the next command that draws a line or surface or patch or image, will automatically trigger clearing the axes. But when you turn hold on before the next round of drawing....

[Alejandro Puertolas]

If i understood it correctly im doing multiple things wrong:

First im holding the lines from previous cycles which is causing my legend to duplicate.

And basically the hold off isn`t doing anything because i hold on again before it has time to work.

My question now is where should the hold on be written to hold the lines from a single cycle without also holding the ones from previous cycles?

Thank you in advance

[Alejandro Puertolas]

I tried writing it like this:

for i=1:1:precipitates

if System_Handle.Precipitates{i, 1}.Physical_Properties.IsClusterPhaseType

plot(System_Handle.Cache_DynamicVariables.child_handles(1,1), Time(1:TimeStep_Count,1), MeanRadius.DataTable(1:TimeStep_Count,3 ), 'DisplayName', names{i} , 'color', cc(i,:) , 'LineStyle', '-');

hold(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'on' );

end

end

legend(System_Handle.Cache_DynamicVariables.child_handles(1,1),'Location','best');

hold(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'off' );

This does solve the second problem and lets hold off take effect deleting the lines from previous lines. But this also ignores all the item setting because the first plot does cla.

Is there a way of preventing the settings to be ignored? Should i write the setting after the plotting loop?

[Alejandro Puertolas]

Putting the setting after the loop gives the behaiviour i wanted, thank you very much for the insight on how hold on and hold off works.

for i=1:1:precipitates

if System_Handle.Precipitates{i, 1}.Physical_Properties.IsClusterPhaseType

plot(System_Handle.Cache_DynamicVariables.child_handles(1,1), ...

... Time(1:TimeStep_Count,1), MeanRadius.DataTable(1:TimeStep_Count,3 ), 'DisplayName', names{i} , 'color', cc(i,:) , 'LineStyle', '-');

hold(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'on' );

end

end

xlim(System_Handle.Cache_DynamicVariables.child_handles(1,1), [0, t_end]);

xlabel(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'time in s' );

ylabel(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'mean radius in m' );

set(System_Handle.Cache_DynamicVariables.child_handles(1,1),'XScale','log');

set(System_Handle.Cache_DynamicVariables.child_handles(1,1),'YScale','log');

set(System_Handle.Cache_DynamicVariables.child_handles(1,1),'FontSize',16);

legend(System_Handle.Cache_DynamicVariables.child_handles(1,1),'Location','best');

hold(System_Handle.Cache_DynamicVariables.child_handles(1,1), 'off' );