Hai,
I have an array of elements, I need to shift them cyclically to the left. How could I do it in matlab? Looking forward for your reply.
BSD
MATLAB: How to cyclically shift an array
shift
Related Solutions
I've written a phasemap function for this, built on Kristen Thyng's cmocean phase colormap. It has an approximately constant lightness profile, which places even emphasis on all phase values.
So the first and last rows form a cyclic boundary? Easy peasy. :)
First, make up some garbage data.
R1 = rand(1,10);A = [R1;rand(10);R1];A is a 12x10 array, with the desired property.
Now you want to generate a Savitsky-Golay filter for this problem. Say a window of length 5. I'll arbitrarily pick a polynomial order as 1, so a linear model.
The filter is easy enough to generate, although I know what it will look like in advance.
M = pinv([ones(5,1),(-2:2)']);F = M(1,:);It should be [1 1 1 1 1]/5. A quick check verifies that fact:
FF = 0.2 0.2 0.2 0.2 0.2So we could now use conv2, with the convolution kernel of F.' to do the Savitsky-Golay. In order to force it to be cyclic though, just one more trick. Copy a couple of rows at the top and bottom, the number of which is based on the window length of the filter.
Ahat = [A(10:11,:);A;A(2:3,:)];Afilt = conv2(Ahat,F.','valid');AfiltAfilt = 0.52952 0.60457 0.47513 0.50322 0.50705 0.7234 0.49297 0.50984 0.35622 0.69495 0.48703 0.75185 0.5751 0.57635 0.50425 0.71976 0.59578 0.4411 0.45476 0.72483 0.64224 0.57291 0.48437 0.55766 0.46489 0.67685 0.5031 0.32243 0.54791 0.63962 0.54804 0.41666 0.5809 0.67033 0.46353 0.678 0.54297 0.33712 0.60857 0.50357 0.51663 0.37418 0.47428 0.72159 0.3828 0.52293 0.70295 0.36182 0.70249 0.46339 0.37867 0.27461 0.40356 0.55024 0.40237 0.4292 0.75475 0.46202 0.76706 0.53382 0.40356 0.18139 0.27915 0.43136 0.47726 0.55353 0.60434 0.48566 0.68725 0.52565 0.30876 0.21009 0.26532 0.49641 0.58333 0.42446 0.55892 0.56039 0.56067 0.51497 0.25662 0.40364 0.29951 0.33418 0.57106 0.4526 0.64386 0.61905 0.48827 0.62547 0.30555 0.5171 0.3188 0.22171 0.626 0.5964 0.53163 0.64753 0.41491 0.6742 0.4321 0.59299 0.41492 0.34121 0.56364 0.67361 0.36325 0.58987 0.3041 0.7128 0.52952 0.60457 0.47513 0.50322 0.50705 0.7234 0.49297 0.50984 0.35622 0.69495No problem. Afilt is a 12x10 array,
Afilt(1,:) == Afilt(end,:)ans = 1×10 logical array 1 1 1 1 1 1 1 1 1 1See there was no need to "adapt" the filter kernel. The trick was to properly expand the matrix itself.
Best Answer