Question

1. Write a function in matlab platform for each part as described.
a. Obtains the multiplication of elements of n-sized vector, where n is a positive integer. Name of this function must be “all2”.
b. Obtains the sum of elements of nxn-sized matrix, where n is a positive integer. Name of this function must be “will3”.
c. Obtains the sum of prime factors of an integer. Name of this function must be “be0”.
Example (1): Prime factors of 84 are [2 3 7].
Hint (1): primes(n) returns the vector of all prime numbers until n.
Hint (2): mod(t,k) returns the remaining number where t is divided by k.
d. Obtains the sum of multipliers of an integer. Name of this function must be “well6”.
Example (2): Multipliers of 84 are [2 2 3 7].
Hint (3): You may benefit from the solution in part c.

Answer 1

1. a

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function y = all2(x)
y=1;
for i=1:length(x)
    y = y*x(i);
end

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Command Window >> аїї2( [1 2 3 4]) ans 24 >> аїї2(4) ans 4

1. b

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function y = will3(x)
y=0;

[row_x col_x] = size(x);
if row_x ~= col_x
    error('input to the function will3 must be a nxn matrix where n is a positive integer.');
else
    for i=1:row_x
        for j=1:col_x
            y = y + x(i,j);
        end
    end
end

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Command Window will3([1 2 3;4 5 6]) Error using wills (line 6) will3([1 2 3;4 5 6;7 8 9]) ans 45 willa(t1 2;3 4]) ans 10

1. c

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function y = be0(x)

array_primes = primes(x);

y = 0;

for i=1:length(array_primes)
    if mod(x,array_primes(i))== 0
        y = y + array_primes(i);
    end
end

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Command Window beo (84) ans ї2 >beo(10) ans - 7 be0 (11) ans її

1. d

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function y = well6(x)

array_primes = primes(x);

y = 0;
quotient = x;

for i=1:length(array_primes)
    if mod(x,array_primes(i))== 0
        y = y + array_primes(i);
        quotient = quotient/array_primes(i);
    end
end

% If the final quotient obtained from previous for loop is >1 it is also
% a multiplier and should be added to the sum.

if quotient > 1
    y = y + quotient;
end

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Command Window well6(84) ans 14 well6(10) ans 7 well6(11) ans =