# What does this plot mean? Can an equation be made of it?

1 view (last 30 days)
Blakeley Ficenec on 2 Feb 2023
Commented: Image Analyst on 2 Feb 2023
This is the plot I am trying to get an equation for:
plot((1:N_rel), [e_mean; mean(lambdaSO(1:end-1,:),2)]./e_total, 'ko');
This is what each value is:
N_rel = 20
e_mean = 4.6600e+04
lambdaSO = 20x30 double
e_total = 1x30 double
The first coordinate on the plot is (1, 0.996058).

Image Analyst on 2 Feb 2023
With this:
N_rel = 20;
e_mean = 4.6600e+04;
lambdaSO = rand(20,30);
e_total = rand(1,30);
x = 1 : N_rel;
y = [e_mean; mean(lambdaSO(1:end-1,:),2)]./e_total
y = 20×30
1.0e+05 * 1.2372 0.4987 2.1508 0.6137 1.1839 1.1303 2.2412 0.5112 1.3909 0.5290 0.5288 1.0551 0.6578 0.5781 1.2955 0.9397 2.7138 0.6341 4.5755 0.9004 0.8226 0.8600 0.8630 0.9650 5.6663 0.9112 2.0831 1.7258 0.5786 0.9998 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
plot(x, y, '.-', 'MarkerSize', 20);
grid on;
legend
whos x
Name Size Bytes Class Attributes x 1x20 160 double
whos y
Name Size Bytes Class Attributes y 20x30 4800 double
y is a matrix not a vector like x is. So it will plot columns. Each of the 30 columns of y is like a separate curve. What exactly are you hoping to see?
##### 2 CommentsShowHide 1 older comment
Image Analyst on 2 Feb 2023
Well, like I said, it plots each column in your matrix as a separate curve.

John D'Errico on 2 Feb 2023
Can you get an "equation" for it? No. At least not any more than what you already have. Anyway, an equation involves an equality. You might hope to get an expression that approximates the relation you showed. But you aready have that. And there is no reason you have suggested that anything more meaningful exists, than what you already have.
Blakeley Ficenec on 2 Feb 2023
Thank you. I wanted to try and plot this in excel. I don't understand what the plot is currently doing in MATLAB.

Cris LaPierre on 2 Feb 2023
Edited: Cris LaPierre on 2 Feb 2023
There are likely many equations you could generate that could satisfy the one point you have shared. However, you must take all the points into consideration when coming up with the equation, and you have not shared that.
As John D'Errico said, that process most likely will be an approximation of the data. If that is what you want to do, then you might consider exploring the Curve Fitter app (this does require having the curve fitting toolbox installed).

### Categories

Find more on Weather and Atmospheric Science in Help Center and File Exchange

R2022b

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by