# How do i multiply 2 increasing variables

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Ilker Enes Çirkin on 14 Aug 2020
Commented: Shae Morgan on 14 Aug 2020
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);

Ilker Enes Çirkin on 14 Aug 2020
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 on 14 Aug 2020
To get this you need to use symbolic tool box.
Sara Boznik on 14 Aug 2020
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?

Shae Morgan on 14 Aug 2020
Edited: Shae Morgan on 14 Aug 2020
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

Show 1 older comment
KSSV on 14 Aug 2020
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 on 14 Aug 2020
i am not familiar with meshgrid
Shae Morgan on 14 Aug 2020
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!)

Bruno Luong on 14 Aug 2020
Edited: Bruno Luong on 14 Aug 2020
v0 = (10:1:20);
theta = (30:1:40);
v0_x = v0.*cosd(theta.'); % horizontal .* vertical vectors
v0_y = v0.*sind(theta.');