Page 27 - Applied Numerical Methods Using MATLAB

16 MATLAB USAGE AND COMPUTATIONAL ERRORS
which makes

t = [0.0 0.1 0.2 ... 1.9 2.0]

(Q6) What if we omit the increment between the left/right boundary numbers?
(A6) By default, the increment is 1.
>>t = 0:2
t=012

(Q7) What if the right boundary number is smaller/greater than the left boundary
number with a positive/negative increment?
(A7) It yields an empty matrix, which is useless.
>>t = 0:-2
t = Empty matrix: 1-by-0

(Q8) If we define just some elements of a vector not fully, but sporadically, will we
have a row vector or a column vector and how will it be filled in between?
(A8) We will have a row vector filled with zeros between the defined elements.

>>D(2) = 2; D(4) = 3
D = 0 2 0 3

(Q9) How do we make a column vector in the same style?
(A9) We must initialize it as a (zero-filled) row vector, prior to giving it a value.

>>D = zeros(4,1); D(2) = 2; D(4) = 3
D=0
2
0
3

(Q10) What happens if the specified element index of an array exceeds the defined
range?
(A10) It is rejected. MATLAB does not accept nonpositive or noninteger indices.

>>D(5)
??? Index exceeds matrix dimensions.
>>D(0) = 1;
??? Index into matrix is negative or zero.
>>D(1.2)
??? Subscript indices must either be real positive
integers ..

(Q11) How do we know the size (the numbers of rows/columns) of an already-
defined array?