How to add more data and plot lines to existing plot

I am trying to add a new line to existing plot using "Add Data" in the plot browser. Instead of adding a new line (and a new variable in the plot browser) my old plot line is being replaced.

I was trying to follow the example as shown in the tutorial "second order systems with various damping coefficients". Instead of adding a new plot for T vs ampdecay my old line of t vs x was being replaced.

[Bhimappa]

Add the title "sample mass" to the existing plot

[Image Analyst]

@Bhimappa, why should he do that? Anyway, he most likely won't since his question is 10 years old.

Answer 1

[Image Analyst]

Use

hold on;

after your first call to plot() to avoid subsequent calls to plot replacing your earlier plot curves.

The hold function controls whether MATLAB clearsthe current graph when you make subsequent calls to plotting functions(the default), or adds a new graph to the current graph. 

hold on retains the currentgraph and adds another graph to it. MATLAB adjusts the axes limits,tick marks, and tick labels as necessary to display the full rangeof the added graph. 

hold off resets hold stateto the default behavior, in which MATLAB clears the existinggraph and resets axes properties to their defaults before drawingnew plots.

[Jan]

hold on sets the 'NextPlot' property of the axes to 'add', which can be done manually also.

[Azzi Abdelmalek]

I don't think it's good idea to use hold on to do the same plot, I think it's better to replot new data and old data at the same time. You can't for example use get(gco,'Ydata') to get Y data.

[Jan]

@Azzi: Why do you think that re-drawing is a benefit? The result of adding a new plot is exactly the same, but redarwing all lines takes more time and riquire all lines to have the same number and position of X-values. Therefore I prefer "hold on" or "hold all" .

Answer 2

[Azzi Abdelmalek]

Add your data to your old variables then plot a new curve

Answer 3

[Norma]

Magnifying a Segment of Plot in MATLAB Figure

https://www.youtube.com/watch?v=p8zPaK8gpEg&fbclid=IwAR10g_CkzRT1Hx7lP3_NYvD4qwvXuzWcjV9XKidmh-WrzK8UHrWFyE4z5zM&app=desktop#menu