Question

Matlab

Answer 1

% Many games require the player to roll two dice. The number on each
% die can vary from 1 to 6.
% (a) Use the rand function in combination with a rounding function
% to create a simulation of one roll of one die.

roundnumbers = ceil(6*rand())


% (b) Use your results from part (a) to create a simulation of the
% value rolled with a second die.

% roundnumbers2 =

% (c) Add your two results to create a value representing the total
% rolled during each turn.

% (d) Use your program to determine the values rolled in a favorite
% board game, or use the game shown in Figure P3.20.



%% 3.23
% Impedence is related to the inductance, l, and the capacitance, C
% by the following equation Z_c = 1/omega*c*j and Z_i = omega*L*j.
% For a circuit similar to the one show in Figure P3.22 assume the
% following:

% C = 1 microF
% L = 200 mH
% R = 5 ohms
% f = 12kHZ
% omega = 2*pi*f
% V = 10 volts


c = 1e-6; % micro-farads
L = 200e-3; % milli-hengrys
Z_R = 5; % ohms
f = 12e3; % kilo Hertz
omega = 2*pi*f; % angular frequency
V = 10; % volts in the circuit

% (a) Find the impedence for the capacitor (Z_c) and for the
% inductor (Z_l).

Z_C = 1/omega*c*1i; % impedence for capacitor
Z_L = omega*L*1i; % impedence for inductor

% (b) Find the total impedance Z_T = Z_C + Z_L + Z_R

Z_T = Z_C + Z_L + Z_R


% (c) Find the current by solving Ohm's law for I. V = I*Z_T

I = V/(Z_T)

% (d) Electrical engineers often describe complex parameters using
% polar coordinates, that is, the paremeter has both an angle and a
% magnitude. (Imagine plotting a point on the complex plane, where
% the x-axis represnts the real part of the number.) Use the abs
% function to find the magnitude of the current found in part c, and
% use the angle function to find the corresponding angle.

Answer 2

3.23 I am just wanting my work looked over

Answer 3

for some reason it won't run and i don't see anyting wrong.

Answer 4

@jtvatsim

Answer 5

OK, sorry to keep you waiting... were looking at impedance now?

Answer 6

3.23 looks like its running fine for me.

Answer 7

back.

Answer 8

```
%% 3.23
% Impedance is related to the inductance L, and the capacitance C
% by the following equations:
% Z_L = i*w*L, Z_C = 1/(i*w*c)
%
% For a circuit similar to the one show in Figure P3.22 assume the
% following:
% V = 10 volts, f = 12 kHz, L = 200 mH, C = 1 uF, R = 5 ohm
%

V = 10; % voltage

f = 12e3; % frequency
w = 2*pi*f; % angular frequency

L = 200e-3; % inductance
C = 1e-6; % capacitance
Z_R = 5; % resistive impedance

%% (a) Find the impedance for the capacitor Z_C, and the inductor (Z_L). %

Z_L = i*w*L; % inductive impedance
Z_C = 1/(i*w*C); % capacitive impedance

%% (b) Find the total impedance Z_T = Z_C + Z_L + Z_R %

Z_T = Z_C + Z_L + Z_R; % total impedance


%% (c) Find the current by solving Ohm's law for the current. V = I*Z_T %

I = V/(Z_T); % current
```

Answer 9

^That is what i have... I am running this in a script.

Answer 10

```
Z_C = 1/(i*w*C); % capacitive impedance
```

Answer 11

parentheses are necessary on this line

Answer 12

% Impedence is related to the inductance, l, and the capacitance, C
% by the following equation Z_c = 1/omega*c*j and Z_i = omega*L*j.
% For a circuit similar to the one show in Figure P3.22 assume the
% following:

% C = 1 microF
% L = 200 mH
% R = 5 ohms
% f = 12kHZ
% omega = 2*pi*f
% V = 10 volts


c = 1e-6; % micro-farads
L = 200e-3; % milli-hengrys
Z_R = 5; % ohms
f = 12e3; % kilo Hertz
omega = 2*pi*f; % angular frequency
V = 10; % volts in the circuit

% (a) Find the impedence for the capacitor (Z_c) and for the
% inductor (Z_l).

Z_C = 1/(i*omega*c); % impedence for capacitor
Z_L = omega*L*1i; % impedence for inductor

% (b) Find the total impedance Z_T = Z_C + Z_L + Z_R

Z_T = Z_C + Z_L + Z_R


% (c) Find the current by solving Ohm's law for I. V = I*Z_T

I = V/(Z_T)

Answer 13

is it working like you expect?

Answer 14

no it's not working

Answer 15

it works in the command window

Answer 16

what error are you getting?

Answer 17

error on anothre line of code. I have like 10 problems on one script but I am separating by cell

Answer 18

Undefined function or variable 'thermocouple'.

Error in Homework2 (line 138)
thermocouple; % array of data thermocouple 1, 2, and 3

Answer 19

^that is another problem

Answer 20

>> c = 1e-6; % micro-farads
L = 200e-3; % milli-hengrys
Z_R = 5; % ohms
f = 12e3; % kilo Hertz
omega = 2*pi*f; % angular frequency
V = 10;
>>
>> Z_C = 1/(i*omega*c); % impedence for capacitor
Z_L = omega*L*1i; % impedence for inductor

% (b) Find the total impedance Z_T = Z_C + Z_L + Z_R

Z_T = Z_C + Z_L + Z_R


Z_T =

5.0000e+00 + 1.5066e+04i

>>

Answer 21

that is in the command window though.

Answer 22

How can I help you?

Answer 23

why doesn't run on the script?

Answer 24

haha it runs now

Answer 25

good.

Answer 26

% Many games require the player to roll two dice. The number on each
% die can vary from 1 to 6.
% (a) Use the rand function in combination with a rounding function
% to create a simulation of one roll of one die.

roundnumbers = ceil(6*rand())


% (b) Use your results from part (a) to create a simulation of the
% value rolled with a second die.

% roundnumbers2 =

% (c) Add your two results to create a value representing the total
% rolled during each turn.

% (d) Use your program to determine the values rolled in a favorite
% board game, or use the game shown in Figure P3.20.

Answer 27

so how would I go about solving part b c and d?

Answer 28

`roll_1 = ceil(6*rand())`

`roll_2 = ceil(6*rand())`

`sum = roll_1 + roll_2`

Answer 29

so rand() just makes a NxN matrix? That is all it does?

Answer 30

or maybe

`roll_1 = round(6*rand())`

Answer 31

```
>> help rand
```
rand Uniformly distributed pseudorandom numbers.
R = rand(N) returns an N-by-N matrix containing pseudorandom values drawn
from the standard uniform distribution on the open interval(0,1). rand(M,N)
or rand([M,N]) returns an M-by-N matrix. rand(M,N,P,...) or
rand([M,N,P,...]) returns an M-by-N-by-P-by-... array. rand returns a
scalar. rand(SIZE(A)) returns an array the same size as A.

Note: The size inputs M, N, P, ... should be nonnegative integers.
Negative integers are treated as 0.

R = rand(..., 'double') or R = rand(..., 'single') returns an array of
uniform values of the specified class.

The sequence of numbers produced by rand is determined by the settings of
the uniform random number generator that underlies rand, RANDI, and RANDN.
Control that shared random number generator using RNG.

Answer 32

okay what about part d? I can upload the figure if you give me a sec

Answer 33

roll_3 = ceil(30*rand())

Answer 34

`ceil` and `round` work the same for positive numbers,
the question specifically asks you to use `round`

Answer 35

so instead of using ceil use round?

Answer 36

oh wait a minute `round` and `ceil` are a bit different.

Answer 37

so when we used roll_1 = ceil(6*rand()) the six indicates 6 sides on the dice?

Answer 38

That is the reason why we are multiplying by rand()?

Answer 39

yeah, rand function will return a number in the range (0, 1) (an open range)

Answer 40

we want [1, 6]

so we multiply by 6

and the round up

Answer 41

okay I see.

Answer 42

`roll_3 = ceil(30*rand())`
== `roll_3 = ceil(30*`(0,1)`)`
== `roll_3 = ceil(` (0, 30) `)`
== `roll_3 =` [1,30]

Answer 43

@UnkleRhaukus what are you doing there? Are those all equal to each other?

Answer 44

\(\verb+ceil(6 * rand())+\)
-> \(\verb+rand()+\)creates a random value between 0 and 1,
-> then multiplies it by 6, (number is in \((0,6)\))
-> rounds it to above integer. (number is in \(\{1,2,\dots,6\}\).


It would be a good idea to create function "rolldie" that you can call any time you want.
```
function result = rolldie()
result = ceil(....);
end
```
If you want several results now, you just call \(\verb+rolldie()+\) several times. You can also construct games using this function, e.g.
```
function result = mygame()
d1 = rolldie();
d2 = rolldie();
result = ....... % do something with d1 and d2
end
```

Answer 45

yeah

Answer 46

@reemii okay thanks

Answer 47

@UnkleRhaukus so how would I use round instead of ceil? You said they are a bit different from each other.

Answer 48

i think `ceil` is more appropriate that `round` here

Answer 49

*than

Answer 50

@UnkleRhaukus okay sounds good. I think the last part on 3.23 I have figured it out.

Answer 51

It is \(possible\) to use \(\verb+round+\) here but you must choose the right transformation of \(\verb+x=rand();+\).

Make sure that \(\verb+round+\) is applied in such a way that:
- the values returned are really 1,2…,6
- the probability that 1 is returned = the probability that 2 is returned = \(\dotsb = \dfrac16\).

If you use \(\verb+round(6 * rand())+\), it will be incorrect: the value 0 will be returned if \(\verb+6*rand()+ < 0.5\). The correct way to do this is:

\(\verb$result = round(0.5 + 6 * rand())$\)

because 0.5 * 6*rand() will map (0,1) onto (0.5, 6.5) and round( will send any number of (0.5,1.5) onto 1, any number of (1.5,2.5) onto 2, etc.

Answer 52

*typo in last sentence*: because \(\verb$0.5 + 6 * rand()$\) will map ....

Answer 53

Okay I am out. @reemii and @UnkleRhaukus thank you for your help. If I have any other question regarding MATLAB I will ask. Night

Answer 54

yw. ciao

Answer 55

g'night!