MATLAB matrices, vectors, and equations help!!!

I'm currently trying to compute values of two different Variables, but the problem is that, while one equation is working, the other isn't. Here is my current code with my matrices included.

INITIAL MATRICES/ VECTORS:

X =

NaN

0.2200

0.3000

0.4400

0.4900

0.7000

0.8000

0.9000

1.1000

1.0000

1.1500

1.2000

1.2200

1.2600

1.2500

1.2700

1.2000

1.2200

1.2600

1.2000

1.2200

1.2600

1.2000

1.2200

1.2600

1.2500

t =

NaN

0

4

7

10

13

16

22

25

30

33

36

40

48

51

55

60

80

100

120

140

160

180

200

220

240

%% Problem 1

%{

X=Cell Mass Concentration (g/L)

U= Cell Mass Yield Per Carbon Monoxide gcells/mmolCO

t= Time (hours)

Mu= Specific Growth Rate

X1=X(1:end-1)

X2=X(2:end)

t1=t(1:end-1)

t2=t(2:end)

Mu=(X2-X1)/(t2-t1)

U=(X2-X1)/CO

%}

X1=X(1:end-1)

X2=X(2:end)

t1=t(1:end-1)

t2=t(2:end)

Mu=(log(X2)-log(X1))./(t2-t1);

U=(X2-X1)/CO;

%{

ans

Max value of Cell Mass Yield per Carbon Monoxide = max(Yx)

Max value of Cell Mass Concentration = max(Mu)

%}

% Find max values of specific growth rate(Mu) and cell mass yield(Yx/co)

Mumax=max(Mu);

Umax=max(U);

% Answer Display

sprintf('The maximum specific growth rate is %f, and the maximum cell mass yield per CO is %f',Mumax, Umax)

The problem with my current code is that, while Mu is equalling a vector which 26x1, U is equalling a matrix which is 25x26. I need U to also be a 26x1 vector, because currently my max value for U is 0.00000.

Answer 1

[Star Strider]

The ‘CO’ variable is missing.

If ‘CO’ is a row vector rathar than a column vector, that could be the problem. If so, the solution would be to transpose it to a column vector. Remember to do element-wise operations, if that is what you want.

[Grace Rembold]

CO is a column vector just like X and t.

CO =

NaN

0

7.7100

11.2600

13.9200

19.8000

21.2500

20.1300

20.9100

21.3900

21.9900

23.8700

22.2700

22.7300

22.2400

22.3100

22.2300

21.9300

22.6000

22.0100

21.8100

21.5600

21.6000

20.6200

19.1700

18.8700

also, I'm very bad at using MATLAB. My first version of this code worked fine, and there was a "." in the equation somewhere i just have no idea where.

[Star Strider]

This produces a (25x1) vector:

U=(X2-X1)./CO(2:end);

That is likely where the dot operator was, however the sizes of the vectors must also be the same.

I do not completely understand what you are doing, especially with respect to ‘X1’ and ‘X2’, and ‘t1’ and ‘t2’.

[Grace Rembold]

Thank you, that is where the dot operator was.

the t1, X1, etc. have been removed for everything now. they were just placeholders that made it easier to read while i figured out the actual equation. I'm basically recreating a given equation based off of excel data and then using the equations to plot relationships between the data. in further problems. But to be honest, i'm nto really sure whats going on either :/

[Star Strider]

My pleasure.

If my Answer helped you solve your problem, please Accept it!