Question

3. Write a function called sort3 that takes a 3-element vector as its sole arguments. It uses if-statements, possibly nested, to return the three elements of the vector as three scalar output-arguments in nondecreasino-roer , i.e., the first output argument equals the smallest element of the input vector and the last output argument equals the largest element. NOTE: Your function may NOT use any built-in functions, e.g., sort, min, max, median, etc. (5 points) (bonus question). Write a function called poly_val that is called like this p-poly val (co,c,x),where c0 and x are scalars, c is a vector, and p is a scalar. If c is an empty Otherwise, p equals the polynomial, where N is the length of the vector c. Hint: you may want to use the operator. To check if a vector is empty, use function isempty to check if a variable is a scalar, use isscalar (5 points)

Answer 1

3.

% Matlab function that takes a 3-element vector and returns three-scalar
% output arguments in non-decreasing order.
% first = smallest element of data
% last = largest element of data
function [first, second, last] = sort3(data)
if(data(1) < data(2))
if(data(1) < data(3))
first = data(1);
if(data(3) < data(2))
second = data(3);
last = data(2);
else
second = data(2);
last = data(3);
end
else
first = data(3);
second = data(1);
last = data(2);
end
else
if(data(2) < data(3))
first = data(2);
if(data(1) < data(3))
second = data(1);
last = data(3);
else
second = data(3);
last = data(1);
end
else
first = data(3);
second = data(2);
last = data(1);
end
end
end
%end of function

Output:

[first,middle, last]-sort3 ([2,3,11) first 1 middle- 2 last 3

4.

% Matlab function to calculate the value of the polynomial given x value
% and coefficients in vector c and constant value in c0
function p = poly_val(c0,c,x)
% if c is empty
if(isempty(c))
p = c0;
else
if(isscalar(c)) % if c is scalar
p = c0 + c*x;
else % if c is vector
p = c0;
for i =1:length(c)
p = p + (c(i)*(x.^i));
end
end
end
end
%end of function

Output:

>> poly val(5, [1,2) ans >>poly_val (5, 3,2) ans >> poly val (5, [3,2],2) ans 19