add parameters to the figure in Matlab

Question

I have a plot in Matlab as following, I want to add some parameters to the figure like the figure which I have added. Could you help me with how to solve that? Thank you so much.

delta = 0.5;
I1=2;
I2 =4;
T = 5;
tau = 0.5;
b = 8;
a = 6;
c = 8;
d = 4;
t = [0:0.001:5];
y =(a-b*exp(-tau*t)).*(t>=0 & t<delta*T )+(-d+c*exp(-tau*(t-delta*T))).*(t>=delta*T & t<=T);
plot(t,y ,  'b',  'LineWidth',1.8)
hold on

x = [0:0.01:12];

max = 4*ones(1,1201);
min = -2*ones(1,1201);
z = 0*ones(1,1201);
plot(x,max ,  '--g',  'LineWidth',1)
hold on 
plot(x,min ,  '--g',  'LineWidth',1)

plot(2,min ,  '--g',  'LineWidth',1)
plot(x,z ,  'k',  'LineWidth',1.7)

axis([0 6 -4 6])

Answer 1

I think this code might generate something close for what you are looking. It is important to say that the arrows for x and y can be added using the same "annotation command".

delta = 0.5;
I1=2;
I2 =4;
T = 5;
tau = 0.5;
b = 8;
a = 6;
c = 8;
d = 4;
t = [0:0.001:5];
y =(a-b*exp(-tau*t)).*(t>=0 & t<delta*T )+(-d+c*exp(-tau*(t-delta*T))).*(t>=delta*T & t<=T);
plot(t,y ,  'b',  'LineWidth',1.8,'DisplayName',"Data")
% Change the y limits
ylim([-4 6])
hold on

% %% Set the horizontal lines and its name in the y axis
% MAX LINE - Create a yline Cte along the plot
hLine = yline(4);
hLine.LineWidth = 1;
hLine.Color = "g";
hLine.LineStyle = "--";
hLine.DisplayName = "Max Line";
% MIN LINE - Create a yline Cte along the plot
hLine = yline(-2);
hLine.LineWidth = 1;
hLine.Color = "g";
hLine.LineStyle = "--";
hLine.DisplayName = "Min Line";
% Zero LINE - Create a yline Cte along the plot
hLine = yline(0);
hLine.LineWidth = 1.7;
hLine.Color = "k";
hLine.LineStyle = "-";

% Change the "name" in the y axis
hAxis = gca;
% Get index 
%  - when y is equal to "Max" in this case 4
%  - when y is equal to "MIN" in this case -2
idx = hAxis.YTick == 4;
hAxis.YTickLabel{idx} = 'X';
idx = hAxis.YTick == -2;
hAxis.YTickLabel{idx} = 'Y';

% %% Set the vertical lines and its name in the x axis
% Delta LINE - Create a xline Cte along the plot
hLine = xline(2.5);
hLine.LineWidth = 1;
hLine.Color = "k";
hLine.LineStyle = "-";
% MIN LINE - Create a yline Cte along the plot
hLine = xline(4);
hLine.LineWidth = 1;
hLine.Color = "k";
hLine.LineStyle = "-";

% Add the notes
annotation('textbox',[.55 .2 .3 .3],"String","Delta",...
    'FitBoxToText','on','LineStyle','none')
annotation('textbox',[0.8 0.2 .3 .3],"String","A",...
    'FitBoxToText','on','LineStyle','none')

The previous code will generate the next figure.