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Andrei Bobrov


4,411 total contributions since 2011

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Answered
how to reverse a random permutation of a matrix to get back the original matrix?
key1 = randi(398,4,5); s = size(key1); p = reshape(randperm(numel(key1)),s); O = key1(p); [~,ii] = sort(p(:));...

3 days ago | 0

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Answered
how to use "ln" function on each elemnets of the matrix?
Here |yourmatrix| - double array. log(yourmatrix)

6 days ago | 0

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Answered
Frequency of unique rows
a = [0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 2 0 0 0 2]; [aa,~,c] = unique(a,'rows'); out = ...

7 days ago | 1

| accepted

Answered
How to find a specific row in the matrix
M = [1 8 11 2.1; 2 10 12 1.8; 1.5 9 10 2.2; 1 9 10 1.9]; [~,ii] = min(M(:,end)); out = M(ii,1:3);

7 days ago | 1

Answered
Changing block row matrix to block column matrix?
[EDIT] B = 2; % the number of blocks [m,n] = size(c); out = reshape(permute(reshape(c,m,n/B,[]),[1,3,2]),m*B,[]);

7 days ago | 2

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Answered
How to concatenate the rows of char array containing 8-binary string ?
a = string('10111011'); b = string('10101010'); a + b

8 days ago | 0

Answered
How do merge two vectors into one, like in intersect. but now with a small margin
out = A(ismembertol(A,B,1,'DataScale',1));

8 days ago | 0

Answered
How to Import excel document with alot of sheets that does not ignore date in first column
fn = 'Path_to_your_file\MachineLearning.xlsx'; [~,sheet_name] = xlsfinfo(fn); sheet_name = strrep(sheet_name,' ','_'); ...

8 days ago | 0

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Answered
what should be the program for following output?
>> a0 = {'Sr_no' 'Threshold' 'TP' 'TN' 'FP' 'FN' 'FAR' 'FRR' 'GAR'}; a=[1 0 0 100 0 100 0 1 0 2 0.1 19 100 0 81 0 0.81 1...

8 days ago | 0

Answered
how can i apply 1 of k coding scheme on 2D MATRIX
C = randi([1,3],2,4) [m,n] = size(C); k = max(C(:)); out = zeros(n,k,m); [ii,kk] = ndgrid(1:m,1:n); out(sub...

8 days ago | 0

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Answered
Finding neighbours in a matrix
Let |a| - your double array. m = size(a)+2; b = nan(m); b(2:end-1,2:end-1) = a; iii = reshape(1:numel(b),m); ii...

9 days ago | 0

Answered
Convert cell array to two row vector
cell2mat(hvix(:)')

9 days ago | 0

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Answered
sum of consecutive months value in an array
a = [1988 6 223.12 1994 7 1033.0 1994 8 464.67 1995 9 251.33 1997 6 121.41 1997 8 624.58 1999 9 221.60 20...

9 days ago | 0

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Answered
table name res5500 ,row size 762,three column, third column each row have different length,compare the value of each row is same or different. count number of same row and different row, please help me
f = fopen('path_to_file\res_5500.csv'); c = textscan(f,'%s','delimiter','\n'); fclose(f); n = cellfun(@numel,re...

9 days ago | 0

Answered
How do I create a loop to increment the number of terms of a function?
m = @(x)1+a(:).'*(x - b(:)) use >> a = [1 2 3 4 5]; b = [6 7 8 9 10]; m = @(x)1+a(:).'*(x - b(:)); ...

11 days ago | 0

Answered
why do I need to add eps ?
To avoid the uncertainty of |"0/0"| situation when calculating |z|. When |x = 0| and |y = 0|.

18 days ago | 0

Answered
array indexing with repeated index, index size larger than the array
One way: A = {'a' 'b' 'c' 'd'}; I = [1 1 3 1 1 1 2 2 1]; B = A(I);

22 days ago | 0

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Answered
What is wrong with this code?
for ii = 1:8760 if v(ii)<vci || v(ii)>vco P(ii)=0; elseif vci<=v(ii) && v(ii)<vr P(ii)=(0....

23 days ago | 0

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Answered
How do convert array x to array z?
or just: [~,~,z] = unique(x,'stable'); or more [~,z] = ismember(x,[4 8 5]);

23 days ago | 0

Answered
how to reverse an integer
flip(sprintf('%d',4530),2)

28 days ago | 0

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Answered
how to take a matrix of certain values taken from the matrix
q = 125; [~,inx] = mink(abs(A(:,2) - q),2); B = A(inx,:); or for old MATLAB q = 125; [~,inx] = sort(abs(A(:,2) ...

28 days ago | 0

Answered
Get the max value and the indices of max value across a series of matrices
Let A - your cell array (25 x 50) with double matrix 128 x 128. n = size(A,1); maxvalue = cell(n,1); maxidx = cell(n,...

1 month ago | 1

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Answered
how to have a vector that counts how many repetitive numbers there is in another vector?
out = [(1:51)',histcounts(A,1:52)']

1 month ago | 0

Answered
how can i create 12 monthly maxima from a uniform distribution between 0 and 6? (using unifrnd)
R = unifrnd(a,b(end),[1,12]); or R = rand(1,12)*b(end);

3 months ago | 0

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Answered
Collapsing data that are within one integer value of each other
n = diff(z(:)) == 1; lo = [n;0] | [0;n]; nn = [diff([0;n]) == 1;0]; nn(~lo) = 1; out = ceil(accumarray(cumsum(nn),...

3 months ago | 1

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Answered
How to merge adjacent NaN values into single NaN value in a vector?
a = [1 2 3 NaN NaN 0 1 2 NaN 9 8 7 6 NaN NaN NaN 1 1]; lo = ~isnan(a); lo(strfind(lo,[0 1])) = true; out = a(lo);

3 months ago | 0

Answered
Sir, am having the four mat files, which of two contains features from minutie and other two contains feature from invarient moment, can i make fusion of those features by combining it then how?
V = {load('db1.mat'),load('db2.mat'),load('db3.mat'),load('db4.mat')}; n = cellfun(@fieldnames,V,'un',0); V1 = cellfun...

3 months ago | 0

Answered
Error in following code while converting cell to matrix
fusion = cell2mat(cat(1,out{:})); or just V = {load('db1.mat'),load('db2.mat'),load('db3.mat'),load('db4.mat')}; ...

3 months ago | 0

Answered
How to create matrix from descending number of vector elements without loop?
A = [1 2 5 3 4]; n = numel(A); out = ones(n,1)*A.*flip(triu(ones(n)),2); or just ( |MATLAB >= R2016b|) out = A...

3 months ago | 0

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