How to draw a line of best fit on filtered discrete data sets
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How can i draw a line of best fit on a subset of the full data set?
I want a line of best fit but only using the data in blue below
So ignore the green, yellow, orange, red, only use the blue part
Now that is easily filtered down to, so know which parts are the blue part is easy, but getting to somehow draw a line of best fit to only use the blue is the challeging part
I can filter the data set to only show the data i want to use for the line of best fit, as shown in graph below
Now all i need it to find a way to draw a line of best fit on this data set, but when i try polyfit and other best fit functions, it gets all messed up
I'm assuming because of the gaps in the dataset.
So how can i draw a line of best fit for the chart above?
Mathieu NOE on 4 Jun 2021
I used this simple example and created a gap in the data (not NaN's)
there is no problem to use polyfit in that situation
% Example: simple linear regression with polyfit
% Fit a polynomial p of degree 1 to the (x,y) data:
x = 1:100;
x(x>25 & x <75) = ;
y = 0.3*x + 2*randn(1,length(x));
p = polyfit(x,y,1);
% Evaluate the fitted polynomial p and plot:
f = polyval(p,x);