How can I plot and reach to this figure ?

I want to know the code that can I get same figure about Biorhythms ?

A) write a MATLAB code that can display Biorhythms for a person given their date of birth and the target date. Your Program should be able to plot the Biorhythms for a suitable spread around the target date (i.e., 30 days).

B) Annotation of the plot and curve with day and date.

C) Create a User‐Defined function to Calculate the total number of days between birthdate and target date. Create your own logic. Do not use any built‐in function (i.e., datenum) to calculate the total number of days

D) Demonstration of features that you have created/coded to add value to graph. · Demonstration that code works correctly using representative samples.

Answer 1

[Star Strider]

birthday = datenum(year, month, day);
t = 0:ceil(datenum(now)-birthday);
Physical = sin(2*pi*t/23);

The rest would be calculated similarly.

EDIT — (5 Aug 2020 at 22:34)

You did not previously state that this was an assignment. My initial impression was that you were simply interested in this.

[Khalid Sultan]

Thank you for your answer but can you solve with these points ?

[Star Strider]

My pleasure.

I can, yes.

The point of this homework assignment is that you need to figure it out yourself.

[Adam Danz]

The structure for most of the assigment is given to you in the two answers you received.

Now you have to put in the time to learn.

[Khalid Sultan]

function Biorhythms()
from=input('Birth Data [yyyy,mm,dd] :');
to=input('Target Data [yyyy,mm,dd] :');
n=datenum(to)-datenum(from)-1
t=0:1:n+30;
Physical=sin(2*pi()*t/23);
Emotional=sin(2*pi()*t/28);
Intellectual=sin(2*pi()*t/33);
t=t+datenum(from);
t=t(length(t)-61:length(t));
Physical=Physical(length(Physical)-61:length(Physical));
Emotional=Emotional(length(Emotional)-61:length(Emotional));
Intellectual=Intellectual(length(Intellectual)-61:length(Intellectual));
hold on
plot(t,Physical,'blue','LineWidth',2);
plot(t,Emotional,'red','LineWidth',2);
plot(t,Intellectual,'green','LineWidth',2);
datetick('x','dd-mmm')
grid on
legend('Physical','Emotional','Intellectual');
axis([min(t),max(t),-1,1]);
hold off
end

I did what I know .. but it is wrong because i can not know how can plot y axis of -100 to 0 to 100 . Also, the x axis i do not know how will i do it by weeks .

[Adam Danz]

Your assignment states not to use datenum.

Answer 2

[Adam Danz]

I'm not going to do your work for you but I can give you some hints that will get you started. If you are unfamiliar with a function, look it up in the documentation.

1) Define a birthday. You can use datetime(). For example, this is today:

birthday = datetime(2020,08,05);

2) Define a second date which will be used to compute the number of days since the birthday (use datetime again). I'll call this variable endDate.

3) Compute the number of days between birthday and endDate using (fill in the 2 blanks)

daysSinceBirth = days(___ - ___)

4) Create the t variable from the equations you shared. t is a vector of values. Example:

t = linspace(0, daysSinceBirth, 50) where "50" is the number of data points between the min and max.

5) Use sin() to compute the equations you listed in your question. Example (fill in the blank):

y = sin(_____)

6) Create a vector of datetime values that will appear in your x-axis.

dt = birthday + days(t);

7) Use plot() to plot the results: plot(dt,y);

If you get stuck, show us what you tried and I'd be happy to give more hints.

[Khalid Sultan]

thank you very much and i will try now your method

[Khalid Sultan]

function bio()

Birthday=input('Please enter the date of your birthday [dd,mm,yyyy] : ');
Targetday=input('Please enter the date of your targetday [dd,mm,yyyy] : ');
birthday = datetime(Birthday); 
targetday = datetime(Targetday);
daysSinceBirth = days(targetday-birthday);
t =linspace(0,daysSinceBirth,30);
y=sin(2*pi()*t/23);
z=sin(2*pi()*t/28);
w=sin(2*pi()*t/33);
dt = birthday + days(t); 
hold on
plot(dt,y,'blue','LineWidth',2);
plot(dt,z,'red','LineWidth',2);
plot(dt,w,'green','LineWidth',2);
grid on
legend('Physical','Emotional','Intellectual');
hold off
end

I did not access to write figure

I can not know how can i make y-axis (-100 to 100) and the write values to x-axis

[Star Strider]

Note that datetime is also a built-in function, as is linspace, and essentially everything else!

[Adam Danz]

Good point. I wonder what the instructor means or if that's even an accurate description of the assignment.

[Adam Danz]

@Khalid Sultan, to scale a sin function,

y = a*sin(x);

To reformat the datetime axis ticks,

https://www.mathworks.com/help/matlab/ref/datetick.html