How to plot best fit line?
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I have 1700 plot of data in graph. How do I plot the line of best fit? I stored the x and y data in table and the plot them. From the graph, I can see that the graph plotting is upwards. I have read other answers for this kind of question but still confused. Please help. Thank you.
x = score;
y = MOS;
scatter(x,y)
xlabel('score')
ylabel('MOS')
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Accepted Answer
Image Analyst
on 15 Jan 2018
Edited: Image Analyst
on 10 Feb 2021
Use polyfit() and polyval():
% Get coefficients of a line fit through the data.
coefficients = polyfit(x, y, 1);
% Create a new x axis with exactly 1000 points (or whatever you want).
xFit = linspace(min(x), max(x), 1000);
% Get the estimated yFit value for each of those 1000 new x locations.
yFit = polyval(coefficients , xFit);
% Plot everything.
plot(x, y, 'b.', 'MarkerSize', 15); % Plot training data.
hold on; % Set hold on so the next plot does not blow away the one we just drew.
plot(xFit, yFit, 'r-', 'LineWidth', 2); % Plot fitted line.
grid on;
See attached for a full demo.
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More Answers (1)
Jos (10584)
on 15 Jan 2018
if it is just for plotting, the command lsline would do.
x = 1:10 ; y = 2* x + 3 ;
plot(x, y, 'bo') ;
lsline
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