How can I convert indices into a binary matrix?

Hello all, I have a txt file that includes list of selected items (there are 10 items in total). I am reading the file using "readmatrix". I want to create a binary (logical) matrix as in the example below but I am getting "The subscript vectors must all be of the same size." message. How can I fix it? Thanks for the help.

1,3,5     -> 1,0,1,0,1,0,0,0,0,0
1,2,3,7   -> 1,1,1,0,0,0,1,0,0,0
1,2,6,7,8 -> 1,1,0,0,0,1,1,1,0,0
1,2,3     -> 1,1,1,0,0,0,0,0,0,0
...

[Stephen23]

@MByk: please upload a sample data file by clicking the paperclip button.

Answer 1

[Dyuman Joshi]

ItemSet = readmatrix('Test.txt','NumHeaderLines',0)

ItemSet = 31×7

1 5 9 10 NaN NaN NaN 1 5 9 10 NaN NaN NaN 1 5 8 9 10 NaN NaN 1 5 7 9 10 NaN NaN 3 5 9 10 NaN NaN NaN 3 5 8 9 10 NaN NaN 3 5 7 9 10 NaN NaN 3 4 5 9 10 NaN NaN 3 4 5 8 9 10 NaN 3 4 5 7 9 10 NaN

tic
s = size(ItemSet);

%corresponding row values
row = repelem((1:s(1)).', 1, s(2))

row = 31×7

1 1 1 1 1 1 1 2 2 2 2 2 2 2 3 3 3 3 3 3 3 4 4 4 4 4 4 4 5 5 5 5 5 5 5 6 6 6 6 6 6 6 7 7 7 7 7 7 7 8 8 8 8 8 8 8 9 9 9 9 9 9 9 10 10 10 10 10 10 10

%maximum value
m = max(ItemSet, [], 'all');
%subscript values
idx = [row(:) ItemSet(:)];
%check for NaN values
k = isnan(idx(:,2));

out = accumarray(idx(~k,:), 1, [s(1) m])

out = 31×10

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

toc

Elapsed time is 0.010489 seconds.

[MByk]

Thank you Dyuman Joshi.

Answer 2

[Alexander]

Maybe something like the following?

fid = fopen('Item.txt');

A = [];

while(~feof(fid))

syLine = fgetl(fid);

dyA = zeros(1,10);

syLine = ['[' syLine ']'];

dyLine = eval(syLine);

dyA(dyLine) = 1;

A = [A; dyA];

end

A

fclose(fid)

[Stephen23]

"Maybe something like the following?"

But preferably without the evil EVAL. Why do you need it? (hint: you don't)

There are various ways to avoid ugly, evil, inefficient EVAL is this situation, here is just one:

out = nan(0,10);
fid = fopen('Item.txt');
idr = 1;
while ~feof(fid)
    idr = idr+1;
    idc = [fscanf(fid,'%f');fscanf(fid,',%f')];
    out(idr,idc) = 1;
end
fclose(fid);
out

out = 6×10

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

[MByk]

Thank you Alexander and Stephen23.

[Alexander]

Thanks @Stephen23