5th Matlab MCQ paper

mandatory answer

Question 1

Name

Question 2

How to draw a 3D object or a mesh or polygons ?

poly(X, Y, Z, C); where 'X','Y','Z' contains coordinates of vertices of objects to draw and 'C' their colours

patch(X, Y, Z, C); where 'X','Y','Z' contains coordinates of vertices of objects to draw and 'C' their colours

plot3(X, Y, Z, C); where 'X','Y','Z' contains coordinates of vertices of objects to draw and 'C' their colours

patch('Vertices', verts, 'Faces', faces); where 'faces' is an array of indices pointing to the rows of 'verts'. 'verts' contains coordinates of points to draw

Question 3

How to initialize an array ('a') with 1 x n values (values can be 0 or 1, the most important is to have the good size for the array)

a=zeros(n)

a=ones(n)

a=size(n)

a=new array(n)

a=array(n)

a=zeros(1,n)

a=ones(1,n)

a=size(1,n)

a=new array(1,n)

a=array(1,n)

Question 4

A=magic(9); %it returns a 9x9 array
We want to pick the columns 3 to 6 and the rows 3, 6 and 9, and put the values into a new array, 'B'.
Which statement(s) is/are correct ?

B=A(3:9, 3:6)

B=A(3,6,9, 3:6)

B=A([3,6,9], 3:6)

B=A(3, 3:6)+A(6, 3:6)+A(9, 3:6)

B=A(3, 3:6)'&A(6, 3:6)'&A(9, 3:6)

B=[]; for I=3:3:9, B=[B; A(I, 3:6)]; end

I=3; B=[]; while(I<=9), B=[B; A(I, 3:6)]; I=I+3;end

Question 5

How to transpose 'A' (simple transposition not complex transposition) ?

A.'

A*

t(A)

A^

Question 6

Which statement(s) create(s) a break in the execution of matlab and force it to wait 8 seconds before continuing ?

pause(8);

break(8);

wait(8);

Question 7

In a conditional structure, which comparison(s) is/are correct ('a' and 'b' are numbers, not matrices)

a==b

a=b

a<=b

a~=b

a'&b