Plotting sine functions using linspace command

Given:

Find: Create a variable y that calculates the following function for the range of t.

The variable, t, should contain 450 data points, in the interval shown below. You should be using the linspace command for this because you are provided with the number of points in the array.

Don't forget your operators! You are calculating the value of y at each individual element of t.

Once you have your t and y vectors filled with values, plot y as a function of t. Remember that, when using the plot function, there should be 2 input arguments: the horizontal coordinates come first and the vertical come second. Try adding the following code to label your plot:

xlabel('t')

ylabel('y')

title('Plotting Sine Functions')

My Solution: I got as far as to state the following:

t = linspace(-4*pi,4*pi,450);
y = 4*t*sin*(2*t);
plot(t,y)

However I was getting an error in my y...

[Dyuman Joshi]

What exactly is your question?

[Sam Chak]

@Kyle Weaver: Don't forget your operators!

What do you mean?

[Spaceman]

I was having trouble obtaining this plot, due to the error I was getting with my y code line. Operators I believe refer to the element operator .* needed to properly calculate all of the points.

[Spaceman]

This was what was being asked for :

t = linspace(-4.*pi,4.*pi,450);
y = 4.*t.*sin(2.*t); % Might be abusing element operators here, but doesn't hurt
plot(t,y)
xlabel('t')
ylabel('y')
title('Plotting Sine Functions')

Answer 1

[Hassaan]

@Kyle Weaver I recommend 'MATLAB Learning Material' and 'References' for further understanding.

% Define the range of t with 450 data points between -4*pi and 4*pi
t = % write the linspace command here

% Calculate y for each t using the given function: y = sin(t)
y = % write the function 'y' command here

% Plotting y as a function of t
plot(t, y)
xlabel('t')
ylabel('y')
title('Plotting Sine Functions')

grid on

MATLAB Learning Material:

MATLAB Onramp | Self-Paced Online Courses - MATLAB & Simulink (mathworks.com)

References

Generate linearly spaced vector - MATLAB linspace (mathworks.com)

Sine of argument in radians - MATLAB sin (mathworks.com)

---------------------------------------------------------------------------------------------------------------------------------------------------

If you find the solution helpful and it resolves your issue, it would be greatly appreciated if you could accept the answer. Also, leaving an upvote and a comment are also wonderful ways to provide feedback.

Professional Interests

• Technical Services and Consulting
• Embedded Systems | Firmware Developement | Simulations
• Electrical and Electronics Engineering

Feel free to contact me.

[Dyuman Joshi]

@Hassaan, I've already informed you before to not do obvious homework questions on MATLAB Answers, when no effort has been shown.

You should give hints or push them in the right direction instead of doing just posting a complete solution.

[Hassaan]

@Dyuman Joshi Updated!

[Spaceman]

Genius. I thank you for your explanation, and also respect Mr. Joshi's advice about not giving the exact answer, however have to disagree about no effort being shown; it was just omitted in this particular question. FYI this is just practice to reinforce the idea of using the plot function in all its glory. I'm just a MATLAB noob.

[Dyuman Joshi]

@Kyle, that is a part of a pre-defined message that I (and many other contributors) use. It's a like an auto-generated message.

I guess you might have just forgot to attach your code. I hope you won't forget it from now onwards.

As there are many homework questions being asked frequently on this forum without any efforts shown, expecting us to solve it for them, we have became a bit strict about this.

We are always happy to help/guide, but we won't do others hw for them.

A suggestion - You could take the free MATLAB Onramp tutorial to learn the essentials and syntax of MATLAB.

[Spaceman]

Thank you.

Answer 2

[Sam Chak]

It says to plot y as a function of t. You can follow this example to make the plot.

You can learn more about linspace() and plot() in the documentation.

y = @(t) sin(pi*t).*(cos(pi*t));    % create y as a function of t
t = linspace(-pi/2, pi/2, 900);     % use linspace to create 900 points over the range -π/2 < t < π/2
plot(t, y(t)), grid on              % make the plot

[Spaceman]

Genius. What does the @ symbol accomplish here?

[Sam Chak]

@Kyle Weaver, It's a way of creating an anonymous function. Check out this article:

https://www.mathworks.com/help/matlab/matlab_prog/anonymous-functions.html