shift matrix to the right

Hello,

I need to compare 2 matrices. One is 1x1280 and other is 1x5120. So I need to take the 1st one to the other range. How do i do that.

for example: A=[0 0 1 1 0 0 1 1], B=[0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1]. The number of elements in B is an integer multiple of number of elements in A. After shifting I need to subtract A by B.

Any Idea?

[Torsten]

Is it this what you want ?

A = [A,A];

C = A-B

[Nimasha Pilippange]

Unfortunately not.

[Torsten]

After so many people have tried to interprete what you mean by "shift", I think it would be fair to disclose the secret.

[Nimasha Pilippange]

yes thank you for trying. I have attached the figures to make it easy to understand what I need. I need to get both of them in one scale for comparing. My attampt was shift the output 2 values to the range of output 1.

[Image Analyst]

I don't think shifting will do it. You need scaling also.

Plus you didn't explain "subtract A by B". Does that mean

1. Subtract B from A, like C = A - B, or
2. Subtract A from B, like C = B - A

Which is it?

Why didn't any of the answers below work?

Your screenshots look like data that you forgot to attach. Please do so with the paperclip icon. We'll check back later for it, and for your answers.

[Nimasha Pilippange]

Yes I think we need scaling too. Once I get both the data in one range I need to susbstrat one from another. I attached the images again. Let me know if there is any more detail you need.

[Image Analyst]

You forgot to answer my question. Which is it: 1 or 2?

Answer 1

[Image Analyst]

Try this:

markerSize = 30;
% Say a goes from 250 to 4800 and has 60 elements
a = 250 + (4800-250) * rand(1, 60);
% Say b goes from 100 to 900 and has 30 elements
b = 100 + (900-100) * rand(1, 30);
plot(a, 'b.-', 'LineWidth', 2, 'MarkerSize', markerSize);
hold on;
plot(b, 'c.-', 'LineWidth', 2, 'MarkerSize', markerSize);
grid on;
% Rescale b so that it also goes from 250 to 4800
b = rescale(b, min(a), max(a));
% Interpolate b so that it has the same number of elements as a.
bq = linspace(1, length(b), length(a));
b2 = interp1(b, bq);
plot(b2, 'r.-', 'LineWidth', 2, 'MarkerSize', markerSize);
% Find differences
c1 = a - b2;
c2 = b2 - a;
legend('a', 'b', 'b2')

[Nimasha Pilippange]

I used this and it seems working. Thank you very much

Answer 2

[Scott MacKenzie]

Perhaps this is what you are looking for:

A=[0 0 1 1 0 0 1 1]

A = 1×8

0 0 1 1 0 0 1 1

B=[0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1]

B = 1×16

0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1

m = numel(A);
n = numel(B);
Anew(n-m+1:n) = A % shifted to match B with zeros at beginning

Anew = 1×16

0 0 0 0 0 0 0 0 0 0 1 1 0 0 1 1

Answer 3

[Image Analyst]

It appears no one knows what you mean since it's not clearly explained and you didn't give the resulting difference vector. So here is another guess:

A=[0 0 1 1 0 0 1 1];
B=[0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1];
% Resize smaller vector to be the same size as the larger vector.
a2 = imresize(A, size(B), 'nearest')
% "subtract A by B" - whatever that means.  Here are two possibilities
c = a2 - B
c = B - a2

Let me know if either of these is what you want.

Answer 4

[Voss]

Maybe use interp1() (or resample()):

nx = 20;
x = randn(1,nx);
% xr = resample(x,4,1);
xr = interp1(1:nx,x,1:0.25:nx);
figure();
plot(1:nx,x,'-o');
hold on
plot(0.25*(4:numel(xr)+3),xr,'.');
legend({'Original','Interpolated x4'})