linear regression

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lowcalorie
lowcalorie on 12 May 2012
Commented: Image Analyst on 19 Oct 2022
i have a table of data
X = 1,2,3,4,5,6,7,8,9
Y= 4 5 6 9 8 7 4 1 2
how can i plot these points without having a line then using linear regression to find the uncertainty with a 95% confidence interval and plot that?

Accepted Answer

Image Analyst
Image Analyst on 12 May 2012
% Define sample data.
X = [1,2,3,4,5,6,7,8,9];
Y = [4 5 6 9 8 7 4 1 2];
% Do the plotting:
plot(X, Y, 'bo', 'LineWidth', 3, 'MarkerSize', 15);
grid on;
% Maximize the figure window.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Label the various parts of the plot.
fontSize = 20;
title('lowcalorie Plot', 'FontSize', fontSize);
xlabel('X', 'FontSize', fontSize);
ylabel('Y', 'FontSize', fontSize);
coefficients = polyfit(X, Y, 1);
fittedY = polyval(coefficients, X);
hold on;
% Do the plotting:
plot(X, fittedY, 'rs-', 'LineWidth', 3, 'MarkerSize', 15);
legend('Y', 'Fitted Y');

More Answers (2)

Richard Willey
Richard Willey on 14 May 2012
Alternatively, if you have the 12a version of Statistics Tbx
X = [1,2,3,4,5,6,7,8,9];
Y = [4 5 6 9 8 7 4 1 2];
myFit = LinearModel.fit(X,Y);
plot(myFit)

Maria Ghani
Maria Ghani on 19 Oct 2022
i need to run regression to get coeffecient between two variables x, y . my data set is daily from 1995 to 2022 . i need monthly coeffecient between two variables . what command should i need to write please anyone help. my dat afile is attached for detail information. x regress y but how i can get for every month ?
thanks in advance
  1 Comment
Image Analyst
Image Analyst on 19 Oct 2022
Extract out each month's data and then fit them individually using polyfit.
If you have any more questions, then attach your data and code to read it in with the paperclip icon, in a brand new discussion thread (not here), after you read this:

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