# Using values of a differential equation to plot a new graph

James Bennett shared this question 2 years ago

Hi,

Im running a basic SIR model for some students (lots of examples of the site). However, that system of differential equations contains 3 equations. I want to use the individual values of the I' curve over time to plot a 4th, different equation and graph altogether. I cannot seem to do this, no matter how I try. Basically, I would need to obtain the numerical value of I' at every time t (a measure of disease prevalence) and apply a modification to that equation.

Any help is appreciated! 1

Could you add one of these lots of examples in your post? 1 1

The file can be accessed at https://www.geogebra.org/cl...

See the red graph? It's I_t and its part of a differential equation group of 3 equations.

I would like to take that red curve and say multiply it by some factor or function to yield a new plot/equation.

Any ideas? 1

I_t is a locus of points

do this:

l1 = First(I_t, Length(I_t))

LineGraph(x(l1), y(l1)) 1

I don't know if you're a man or a woman, and my wife forgive me, but I could kiss you!

Thanks SO much! Works wonderful! 