Matlab Sheet 2 Arrays

216827 Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 1 of 32 Matlab Sheet 2 Solution

Matlab Sheet 2

Arrays

1. a. Create the vector x having 50 logarithmically spaced values starting at

10 and ending at 1000.

b. Create the vector x having 20 logarithmically spaced values starting at

10 and ending at 1000.

The m-file:

x1=logspace(1,3) x2=logspace(1,3,20)

2. Create a row vector that has the following elements: 8, 10/4, 12ൈ1.4, 51,

tan 85°,ξʹ͸ , and 0.15.

The m-file:

row=[8 10/4 12*1.4 51 tand(85) sqrt(26) 0.15]

In Command Window:

row =

8 2.5 16.8 51 11.43 5.099 0.15

3. Create a row vector in which the first element is 1 and the last element is 43,

The m-file:

row=1:6:43

In Command Window:

row =

1 7 13 19 25 31 37 43

Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 2 of 32 Matlab Sheet 2 Solution

4. Use a single command to create a row vector (assign it to a variable named b)

with 11 elements, such that b = 0 2 4 6 8 10 12 9 6 3 0

Do not type the vector explicitly.

The m-file:

b=[0:2:12 9:-3:0]

In Command Window:

b =

0 2 4 6 8 10 12 9 6 3 0

5. Create two row vectors: a=2:3:17 and b=3:4:15. Then, by only using the name

of the vectors (a and b), create a row vector c that is made from the elements of a followed by the elements of b.

The m-file:

a=2:3:17; b=3:4:15; c=[a,b]

In Command Window:

c =

2 5 8 11 14 17 3 7 11 15

name of the vectors (a and b), create a column vector c that is made from the elements of a followed by the elements of b.

The m-file:

a=[2:3:17]'; b=[3:4:15]'; c=[a;b]

In Command Window:

c = 2 5 8 11 Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 3 of 32 Matlab Sheet 2 Solution 14 17 3 7 11 15

7. A Type this matrix in MATLAB and use MATLAB to carry out the following

Instructions:

a. Create a vector v consisting of the elements in the second column of A. b. Create a vector w consisting of the elements in the second row of A.

The m-file:

A = [3,7,-4,12;-5,9,10,2;6,13,8,11;15,5,4,1];

v = A(:,2) w = A(2,:)

In Command Window:

v = 7 9 13 5 w = -5 9 10 2 Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 4 of 32 Matlab Sheet 2 Solution

8. Create the following matrix by using vector notation for creating vectors with

constant spacing and/or the linspace command. Do not type individual elements explicitly.

The m-file:

A=[130:-20:10; linspace(1,12,7); 12:10:72]

In Command Window:

A= A =

130 110 90 70 50 30 10

1. 2.8333 4.6667 6.5000 8.3333 10.1667 12.0000

12 22 32 42 52 62 72

9. Create the following matrix by typing one command. Do not type individual

elements explicitly.

The m-file:

%alternative C = [linspace(7,7,5); linspace(7,7,5)]

C=7*ones(2,5)

In Command Window:

C =

7 7 7 7 7

7 7 7 7 7

Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 5 of 32 Matlab Sheet 2 Solution

10. Create the following matrix by typing one command. Do not type individual

elements explicitly.

The m-file:

D=[zeros(3,4) [8:-1:6]']

In Command Window:

D =

0 0 0 0 8

0 0 0 0 7

0 0 0 0 6

11. Create the following matrix by typing one command. Do not type individual

elements explicitly.

The m-file:

F=[linspace(0,0,5); zeros(3,2) [1:3;10:-2:6;20:6:32]']

In Command Window:

F =

0 0 0 0 0

0 0 1 10 20

0 0 2 8 26

0 0 3 6 32

Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 6 of 32 Matlab Sheet 2 Solution

12. Compute the length and absolute value of the following vectors:

The m-file:

x = [2,4,7]; ans1=length(x) ans2=abs(x) y=[2,-4,7]; ans3=length(y) ans4=abs(y) z=[5+3i,-3+4i,2-7i]; ans5=length(z) ans6=abs(z)

In Command Window:

ans1 = 3 ans2 = 2 4 7 ans3 = 3 ans4 = 2 4 7 Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 1 of 32 Matlab Sheet 2 Solution

Matlab Sheet 2

Arrays

1. a. Create the vector x having 50 logarithmically spaced values starting at

10 and ending at 1000.

b. Create the vector x having 20 logarithmically spaced values starting at

10 and ending at 1000.

The m-file:

x1=logspace(1,3) x2=logspace(1,3,20)

2. Create a row vector that has the following elements: 8, 10/4, 12ൈ1.4, 51,

tan 85°,ξʹ͸ , and 0.15.

The m-file:

row=[8 10/4 12*1.4 51 tand(85) sqrt(26) 0.15]

In Command Window:

row =

8 2.5 16.8 51 11.43 5.099 0.15

3. Create a row vector in which the first element is 1 and the last element is 43,

The m-file:

row=1:6:43

In Command Window:

row =

1 7 13 19 25 31 37 43

Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 2 of 32 Matlab Sheet 2 Solution

4. Use a single command to create a row vector (assign it to a variable named b)

with 11 elements, such that b = 0 2 4 6 8 10 12 9 6 3 0

Do not type the vector explicitly.

The m-file:

b=[0:2:12 9:-3:0]

In Command Window:

b =

0 2 4 6 8 10 12 9 6 3 0

5. Create two row vectors: a=2:3:17 and b=3:4:15. Then, by only using the name

of the vectors (a and b), create a row vector c that is made from the elements of a followed by the elements of b.

The m-file:

a=2:3:17; b=3:4:15; c=[a,b]

In Command Window:

c =

2 5 8 11 14 17 3 7 11 15

name of the vectors (a and b), create a column vector c that is made from the elements of a followed by the elements of b.

The m-file:

a=[2:3:17]'; b=[3:4:15]'; c=[a;b]

In Command Window:

c = 2 5 8 11 Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 3 of 32 Matlab Sheet 2 Solution 14 17 3 7 11 15

7. A Type this matrix in MATLAB and use MATLAB to carry out the following

Instructions:

a. Create a vector v consisting of the elements in the second column of A. b. Create a vector w consisting of the elements in the second row of A.

The m-file:

A = [3,7,-4,12;-5,9,10,2;6,13,8,11;15,5,4,1];

v = A(:,2) w = A(2,:)

In Command Window:

v = 7 9 13 5 w = -5 9 10 2 Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 4 of 32 Matlab Sheet 2 Solution

8. Create the following matrix by using vector notation for creating vectors with

constant spacing and/or the linspace command. Do not type individual elements explicitly.

The m-file:

A=[130:-20:10; linspace(1,12,7); 12:10:72]

In Command Window:

A= A =

130 110 90 70 50 30 10

1. 2.8333 4.6667 6.5000 8.3333 10.1667 12.0000

12 22 32 42 52 62 72

9. Create the following matrix by typing one command. Do not type individual

elements explicitly.

The m-file:

%alternative C = [linspace(7,7,5); linspace(7,7,5)]

C=7*ones(2,5)

In Command Window:

C =

7 7 7 7 7

7 7 7 7 7

Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 5 of 32 Matlab Sheet 2 Solution

10. Create the following matrix by typing one command. Do not type individual

elements explicitly.

The m-file:

D=[zeros(3,4) [8:-1:6]']

In Command Window:

D =

0 0 0 0 8

0 0 0 0 7

0 0 0 0 6

11. Create the following matrix by typing one command. Do not type individual

elements explicitly.

The m-file:

F=[linspace(0,0,5); zeros(3,2) [1:3;10:-2:6;20:6:32]']

In Command Window:

F =

0 0 0 0 0

0 0 1 10 20

0 0 2 8 26

0 0 3 6 32

Faculty of Engineering Spring 2017 Mechanical Engineering Department Dr./ Ahmed Nagib Elmekawy 6 of 32 Matlab Sheet 2 Solution

12. Compute the length and absolute value of the following vectors:

The m-file:

x = [2,4,7]; ans1=length(x) ans2=abs(x) y=[2,-4,7]; ans3=length(y) ans4=abs(y) z=[5+3i,-3+4i,2-7i]; ans5=length(z) ans6=abs(z)

In Command Window:

ans1 = 3 ans2 = 2 4 7 ans3 = 3 ans4 = 2 4 7