How to download polyparci file and run it with matlab code becsause there iss no polyparci command in-built of MATLAB

clc(); 
xval = [4 8 11 16 17 19 21 25 32 34];
 %X values as given in question 
yval = [0.33 0.9 1.41 1.99 1.7 2.25 2.60 2.71 3.33 4.01]; 
%y values as given in question [p,S]=polyfit(xval,yval,1); 
fprintf('Fitted equation of straight line to the given data is: 
y=%f(x)+%f\n',p(1),p(2));
 ci = polyparci(p,S);
 fprintf('\n95 percent confidence inetrval for the slope coefficient is (%f,%f) and for the intercept is (%f,%f):',ci(1,1),ci(2,1),ci(1,2),ci(2,2)); 
y_1=ci(1,1)*xval+ci(1,2);
 y_2=ci(2,1)*xval+ci(2,2);
 y_3=(p(1)*xval)+p(2);
 figure 
plot(xval, yval, 'o') 
hold on 
plot(xval,y_1) 
hold on 
plot(xval,y_2)
 hold on 
plot (xval,y_3)

Answer 1

[Matt J]

This might be it:

https://www.mathworks.com/matlabcentral/fileexchange/39126-polyparci?s_tid=srchtitle