MATLAB: Add strings with a loop

strings

Hello,

I know its a simple question:

I have a loop.The reult (Name) of the loop is a string.

for j=1:numRows;
Name=Test.Measure(j, 1).name
end

I want this output:

Name = {'x100',
'x187',
'x122',
'x187'};

One additional question if i have a second time or third time the same string like x187 in my result how can i delete the second or third time?

Thank you.

Best Answer

Name =cell(numRows) ; 
for j=1:numRows;
Name{j}=Test.Measure(j, 1).name
end
iwant = unique(Name)

Related Solutions

MATLAB: Vectorization

A simplification - please test if this is faster already, although it is not vectorized:

Names = fieldnames(Data);
for i = 1:length(fieldnames(Data));
  Names_i = Data.(Names{i});
  for j = 1:length(Names_i);
    index = Names_i{j,1}(:, 1)==211;
    Names_i{j,1} = Names_i{j,1}(index, :);
  end
  Data.(Names{i}) = Names_i;
end

If the cells stored in the field are {N x 1} cell vectors, omitting the second index saves time: Names_i{j} instead of Names_i{j,1}.

MATLAB: How to count the number of times a string occurs in a cell array in a vectorized format

Applying the UNIQUE, STRCMP, and REPMAT functions, finding the number of string repetitions in cell arrays can be performed in a vectorized format.

Using the UNIQUE function, one can obtain cell vector, 'unique_names', of length 'm' from vector 'original_names'. The contents of 'unique_names' will be every string that appears at least once.

unique_names = unique(original_names);

Then using the REPMAT function, one can make a matrix, 'X', where the rows are vector 'original_names' repeated 'm' times resulting in an mxn matrix.

X = repmat(original_names,length(unique_names),1);

Similarly, we make a matrix, Y, with vector 'unique_names' repeated over the columns 'n' times, again, creating an mxn matrix.

Y =repmat(unique_names,1,size(original_names,2))

Next, one can use the STRCMP function to compare matrix 'X' and 'Y'. Taking the sum along the rows will give the quantity of times a given string in the cell array occurred.

quantity = num2cell(sum(strcmp(X,Y),2)');

Please see the attached file for a test sample.

Alternatively you can use the HIST-function to count how many times each string occured in the input vector 'A'.

[a b c] = unique(A)
d = hist(c,length(a))

a contains the the same vector A, but without repetitions.

d contains the count of repetitions.

Best Answer

Related Solutions

MATLAB: Vectorization

MATLAB: How to count the number of times a string occurs in a cell array in a vectorized format

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