FOR LOOP MATLAB

Guys I am so sorry i didn't the complete the question before, i was thinking if i can just get started i will be able to continue but i am more confused now...

The full question is: Write 4 lines of code to use a forloop in the variable i to calculate and store the values of t and h=(3+t)t. Continuing with the above and assuming the out variable is h, allocate memory with NaN command for t and h. b. Next we want to change the problem to calculate 3 equations in the same for loop above. The input will still be t but now the 3 output equations are: h1=10cos(t) h2=t+2 h3=sin(t) Assuming we have allocated memory for h1,h2 and h3, what would the new code for the body of the loop be?

Answer 1

[Fangjun Jiang]

Open MATLAB and type "help for" in the Command Window, read the text and there is a good example to show you how to do it.

My guess is that your professor wants you to learn the basics of MATLAB programming.

First:

for i=1:1000
    t(i)=i*0.1; % t probably is the time, increased by 0.1 seconds 
    h(i)=(3+t(i))*t(i);
end

This approach will be slow when the iteration increases because t and h are not pre-allocated.

Second:

    t=nan(1000,1);
    h=nan(1000,1); 
    for i=1:1000
        t(i)=i*0.1; % t probably is the time, increased by 0.1 seconds 
        h(i)=(3+t(i))*t(i);
    end

Third

I hope you can do it yourself. I think I've shown you the door.

[Oluakin]

Thanks

[Oluakin]

Guys I am so sorry i didn't complete the question before, i was thinking if i can just get started i will be able to continue but i am more confused now...

The full question is: Write 4 lines of code to use a forloop in the variable i to calculate and store the values of t and h=(3+t)t. Continuing with the above and assuming the out variable is h, allocate memory with NaN command for t and h. b. Next we want to change the problem to calculate 3 equations in the same for loop above. The input will still be t but now the 3 output equations are: h1=10cos(t) h2=t+2 h3=sin(t) Assuming we have allocated memory for h1,h2 and h3, what would the new code for the body of the loop be?

Answer 2

[Walter Roberson]

For the first part:

for i = 1
  t = t;
  h = (3+t)*t;
end

Perhaps you omitted key parts of the question that described what t is, or how far many iterations the loop was supposed to go?

[Oluakin]

Thanks Walter Roberson: This helped to get start

Yes I did omitted part of the question the full question was

Question: Write 4 lines of code to use a forloop in the variable i to calculate and store the values of t and h=(3+t)t. Continuing with the above and assuming the out variable is h, allocate memory with NaN command for t and h.

I was thinking if i can get started i can finish it but please take a look at it if there is other help you can offer on the rest of the question

[Walter Roberson]

That is the same question as you originally posted. It asks you to calculate t, but does not give any information about how t is to be calculated.

To finish the question *in the form posted*, after the "for" loop, add the two statements,

t = nan;

h = nan;

I do not understand the point of allocating memory for h *after* the loop instead of *before* the loop, but the allocating the memory _before_ the loop would not be "continuing on" as the question requires.

[Oluakin]

The full question is:

Write 4 lines of code to use a forloop in the variable i to calculate and store the values of t and h=(3+t)t. Continuing with the above and assuming the out variable is h, allocate memory with NaN command for t and h.

b. Next we want to change the problem to calculate 3 equations in the same for loop above. The input will still be t but now the 3 output equations are:

h1=10cos(t)

h2=t+2

h3=sin(t)

Assuming we have allocated memory for h1,h2 and h3, what would the new code for the body of the loop be?