1 %The same data is used for the activity. These are provided for you.
2 X = [-2 -1 1 2].'
3 Y = [3 1 0 1].'
5 %Use the length() command to determine the size of the column vector X. Store this value in m.
7 %Set up the appropriate matrix A to find the best-fit parabola of the form y=C+Dx+Ex^2. The
8 %first column of A will contain all 1's, using the ones() command. The second column of A
9 %contains x values that are stored in X. The third column of A contains the squared x values
10 %that are stored in X. Elementwise multiplication of X by itself, using .* operator, will
11 %produce the desired values for the third column.
13 %Calculate the matrix products. These are provided for you.
14 A_transposeA = A.' * A
15 A_transposeY = A.' * Y
17 %Use the backslash operation to solve the overdetermined system. Store this in Soln2.
19 %Define the x values to use for plotting the best-fit parabola. This creates a vector x.
20 %This is provided for you.
21 x = -4: 0.1: 4
22 %Define the best-fit parabola, storing it in yquadratic. Elementwise multiplication of the
23 %x values times themselves to square them is achieved by using .* operator (because x is a vector).
25 %The following sequence of commands plots the data and the best-fit parabola. The command is
26 %provided for you.
27 plot(x, yquadratic, X, Y, 'k*'); grid; shg
