How do i multiply 2 increasing variables

Hello everyone i was wondering if u could help me multiply these two increasing variables. They just do not multiply correctly

v0 = (10:1:20);
theta = (30:1:40);

v0_x = v0.*cosd(theta);
v0_y = v0.*sind(theta);

[dpb]

What do you think is incorrect?

It may not be what you were trying to compute, but the result of the two expressions is certainly what would be expected by MATLAB syntax.

[Steven Lord]

What does "do not multiply correctly" mean in this context?

• Do you receive warning and/or error messages? If so the full and exact text of those messages (all the text displayed in orange and/or red in the Command Window) may be useful in determining what's going on and how to avoid the warning and/or error.
• Does it do something different than what you expected? If so, what did it do and what did you expect it to do?
• Did MATLAB crash? If so please send the crash log file (with a description of what you were running or doing in MATLAB when the crash occured) to Technical Support using the telephone icon in the upper-right corner of this page so we can investigate.

[Sara Boznik]

I think is correct.

[Ilker Enes Çirkin]

i was expecting the code to create the solutions like this,

10*cosd(30) 11*cosd(30) 12*cosd(30) 13*cosd(30) ....

10*cosd(31) 11*cosd(31) 12*cosd(31) ......

10*cosd(32) 11*cosd(32) ......

10*cosd(33) .......

[KSSV]

To get this you need to use symbolic tool box.

[Sara Boznik]

for v0 = 10:1:20;
for theta = 30:1:40;
v0_x = v0.*cosd(theta)
v0_y = v0.*sind(theta)
end
end

Do you need this?

Answer 1

[Shae Morgan]

Is this more what you were looking for?

v0 = (10:1:20);
theta = (30:1:40);
for i= 1:length(v0)
    for j = 1:length(theta)
        v0_x(i,j)=v0(i)*cosd(theta(j));
        v0_y(i,j)=v0(i)*sind(theta(j));
    end
end
v0_x
v0_y

[Ilker Enes Çirkin]

yes this is correct, thank you

[KSSV]

If you wanted that..simply use:

v0 = (10:1:20);
theta = (30:1:40);

[v0,theta] = meshgrid(v0,theta) ; 

v0_x = v0.*cosd(theta);
v0_y = v0.*sind(theta);

[Ilker Enes Çirkin]

i am not familiar with meshgrid

[Shae Morgan]

meshgrid() is another great solution here

x=[1 2 3]; %x array
y=[3 2 1]; %y array
[X,Y]=meshgrid(x,y) 

%X is a length(y) long set rows of x 
%Y is a length(x) long set of columns of y

using these matrices with the point multiplication will give the same outcome. The for-loops feel more intuitive and are visually understandable as you read through the code, but meshgrid requires fewer lines and a little more understanding of what it's doing.

In the end it's preference. I prefer code readability (or familiarizing yourself with new functions so you can improve readability!)

Answer 2

[Bruno Luong]

v0 = (10:1:20);
theta = (30:1:40);

v0_x = v0.*cosd(theta.'); % horizontal .* vertical vectors
v0_y = v0.*sind(theta.');