How the error value appears in the graph?

Hello, I am trying to plot the difference between two polynomials some of graphs I could not get the value of the error on it like the following graph.

so what I can do to make the value of the error appears in the graph?

Error=abs(p1-p2);

[Rik]

What is the code that you are using and how exactly to do want the error to be shown?

Answer 1

[Walter Roberson]

hold on
plot(x, Error, 'r')

where x is the name of the variable being used for the x axis.

Note that it is possible that the error is small enough that it would not be visible on the graph except as a (red) line against the bottom. For example if the error were about 1E-15 then it would only be 1/10000 the span of your y axes.

[Momo]

Yes, I did that with different values for the coefficients of the polynomial but not all the graphs have the number in the corner (X10^-11), I want to show this number in all cases.

[Rik]

You mean you want to show x10^0? That is not an error, that is a scale for the y-axis.

[Momo]

yes, how can I show it?

[Walter Roberson]

ax = gca;
ax.YAxis.Exponent = 0;

this would disable using the exponent on the Y axis.

If you use a value other than 0 then that exponent will be used; for example you can use a value of -1 or 1.

However, if you want 10^0 to be specifically marked then you have to use an exponent of 0 and then text() the 10^0 into place.

[Momo]

Thank you so much