00:01
Here we have some data on the number of nodes and the runtime in seconds because we're looking at the relationship between app runtime and the number of nodes in the network.
00:13
So here's the data.
00:14
I'm going to go to desmos and plot the data.
00:17
And so i did that down here.
00:20
Here's the data.
00:21
Here's the plot.
00:21
So it looks, there's a curve to it.
00:23
So it's definitely not linear.
00:25
And so then we're told to test two patterns.
00:32
Our quadratic function and an exponential function because it definitely has that appearance to it.
00:42
It could be quadratic, you know, it could be a curve that kind of comes along like this and right, it would go like that.
00:51
It could be exponential, which has that same kind of curve, the similar kind of curve to it, but they're not the same.
00:57
So let's test them out.
01:01
So here is the quadratic.
01:06
And you just put in the, desmos is nice, you put in the values just like that.
01:12
The little tilda to denote regression, you're telling it to do a regression.
01:18
So there's the little screenshot of it.
01:22
There's the data, so it fits kind of, but it's not that, you know, there's some gaps here.
01:30
Let's go, and here are the parameter values, a, b, and c.
01:34
A is your constant on, the coefficient on your x squared term.
01:38
Here's your coefficient on your x term, and then the constant value, 9 .29.
01:43
All right, now let's look at the exponential.
01:53
So there's the format we use.
01:55
Oh, and that's a much better fit than the quadratic.
01:59
Now let's look at them side by side.
02:05
So you can see the quadratic fits, but not quite as good as this exponential.
02:10
Just visually, that exponential fits a better fit.
02:16
So we're going to say it's this one.
02:17
We're going to go with that.
02:20
You know the parameter values for a.
02:22
And b.
02:25
All right.
02:26
So which regression model appears to provide a better fit, exponential.
02:31
I mean, yeah, there we go.
02:32
It just fits better.
02:34
Also has a larger r squared value, which isn't the end -all bl of how you assess the fit of a model, but it's a good indicator.
02:42
And that has a higher r -squared value than the quadratic.
02:49
Right.
02:50
So now we want to estimate the runtime for 3 ,500 nodes and 6 ,000 nodes.
02:58
And then we also want to calculate the derivative, ttdm, at those same points, 3 ,500 ,000.
03:05
All right, so for that, here's the, here's the function, t of n, right, those are a value and b value, evaluated at 3 ,5006 ,000.
03:20
Here are the values, 7 ,216 seconds, for 3 ,500 notes, and then 107 ,22 seconds for 6 ,000.
03:31
So now we want to find the dt, dn.
03:34
So i'm going to write it as t equals a, b to the n.
03:41
You could put in the parameter values, but just to make things easier on us, i am going to leave the general a and b parameters, just a and d.
03:52
So we're going to take the derivative of this...