# Matlab Lab Assignment A7

This assignment is designed only to get you to practice
using Matlab and to

learn its basic operations . It is not terribly long, and you should be able to
do

most of it during your lab on the last week of classes. It counts as a lab, and

it also counts as an assignment: it will be graded, and the grade will be count

toward your final weighted total.

No groups for this assignment . Do it by yourself.

Submit on the CMS a file named a7.m that contains: (1) as a comment, your

name and your netid (2) the answers to the questions below. Most of the answers

are matlab expressions, statements, or functions. When answering a question,

first get it working correctly in the Command- line window . When it works

properly, copy it to file a7.m. Label the answers with the question number and

put them in ascending order. If an answer is not a matlab expression, statement,

or function, then make the answer a Matlab comment.

Do not use loops in this assignment.

WE WILL NOT ATTEMPT TO EXECUTE YOUR FILE a7.m! Think of

it simply as a text file and just put things into it.

**1 Matrix Operations**

1. Write assignment statements that assign these two
matrices to A and B:

2. Type an expression to catenate B’s columns to A’s rows, resulting in the

following matrix:

3. Type an expression to catenate B’s rows to A’s columns resulting in the

following matrix:

4. Try calculating A + B and explain what happens.

5. The previous expression doesn’t work due to dimensions mismatch, now

do the following. (Remember that A^{t} is the transpose of A, which is found

by interchanging rows and columns.)

(a) Calculate the following two matrices : C_{1} = A^{t}+B and
C_{2} = A+B^{t}.

(b) Write a one- line expression that checks whether
;
This expression

should return 1 if the equality holds and 0 otherwise. (Hint:

use functions find and isempty).

6. Type an expression that results in a 4x5 matrix all of
whose elements are

zeros (don’t type the elements one by one !)

7. Type an expression that results in a 3x4 matrix all of
whose elements are

equal to 5. (don’t type the elements one by one !)

8. Type an expression that creates a vector
(one-dimensional array) whose

elements are the odd numbers in the range 1..23.

9. Type a one-line expression (don’t type the elements one
by one) that

results in the following matrix:

10. Write an expression that results in a matrix each element of which is the

square of the corresponding element from matrix D_{1} in (10), i.e.

11. Write a one-line expression whose value is this sum :

3 + 6 + 9 + 12 + 15 + . . . + 297

Use function sum.

12. Define the following two arrays:

Write an expression that will calculate the following sum based on v1 and

13. Given are two series:

Write a one-line expression whose value is the first 10
elements of the series

Hint: Use function cumsum.

## 2 Functions and Plots

1. Write a function (it should not use loops) whose
parameter is a matrix

with an odd number of rows and that yields the matrix reflected over its

horizontal symmetric axis. The input matrix has at least 3 rows . For

example, for the argument matrix:

the function returns this matrix:

Hint 1: Use function size to determine the number of lines. [num_{rows}] =

size(D_{in}, 1).

Hint 2: If you think that you need an integer division (though you really

don’t need one) use matlab function floor.

2. Plot the sin function over the range [−2 × π, . . . , +2
× π]. The step size

should be 0.1. Your expression should be a one-line expression. You can

use the matlab constant pi.

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