Making two 3D vectors the same length

Hi,

I have two vectors, vector_static and vector_dynamic which both contain x, y ,z coordinates, however vector static is 421X3 and vector dynamic is 489x3 in length. How do I pad vector static with zeros at the end so that both vectors are the same dimension? I need them to be the same dimension to carry out the dot product on them, so to calculate the angle between. The data is also only changing in the y and z planes so I would only need to dot these components, however, any help regarding changing the dimesions of the matrix would be greatly appreciated.

Thanks in advance

The code I have so far is:

%%Points on pendulum

%Point 1 S =Source Static

point_1_S = [SourceSx, SourceSy, SourceSz];

%Point 1 D =Source Dynamic

point_1_D = [SourceDx, SourceDy, SourceDz];

%Point 2 S = Fusion static

point_2_S = [FusionSx, FusionSy, FusionSz];

%Point 2 D = Fusion dynamic

point_2_D = [FusionDx, FusionDy, FusionDz];

% Creating a vector between the fusion and source sensors

Vector_static = point_2_S - point_1_S;

Vector_dynamic = point_2_D - point_1_D;

%Calculate the angle between vectors

A = cat(4,Vector_static); % Combine the three components in the 4th dimension

B = cat(4,Vector_dynamic); % Ditto

C = cross(A,B,4); % Take the cross products there.

ang_SD = atan2(sqrt(dot(C,C,4)),dot(A,B,4));

Answer 1

[Scott MacKenzie]

Given that your question is...

How do I pad vector static with zeros at the end so that both vectors are the same dimension?

then here is a simply way to achieve this:

% test matrices, sized as per question
vStatic = rand(421,3);
vDynamic = rand(489,3);

% pad with zeros so both are same size
vStatic(end:size(vDynamic,1),:) = 0;

Result:

[alexandra ligeti]

Thank you so much. This works so well. Appreciate the help.