Storing a row of data into a cell array if it satisfies a condition, if not then disregard and move onto the next row

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mel1708 2020-3-14

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评论： mel1708 2020-3-16

I am trying to sort data into cell arrays according to whether or not they satisfy the if statement. CellPosition is a 10x3 double and CurrentCellPosition is a 1753x3 double (x, y, z coordinates). Basically I want to loop over i (the number of cell positions) and find the difference between the first row of CellPosition and every value in CurrentCellPosition, then I want it to select the CurrentCellPosition(s) which lie within the ranges in the if statement and place them in the first element of a cell array. I then want it to do the same thing for each i (from 1 to 10) leaving me a 1x10 cell array. My code below runs alright but when it comes to writing the values to a cell array I can't seem to figure out where I am going wrong. Right now it is just writing all 1753 elements to each of the 10 elements in the cell array.

 CellRadius = 1 * 10^4 %nm
 NucleusRadius = 7 * 10^3 %nm
 NumberofCells = 10;
CellPosition = csvread('cell.csv');
for i = 1:NumberofCells
    for j = 1:length(Damage)
  
        CurrentCellPosition = cell2mat(Damage(:,2:4));
  
        X = abs(CurrentCellPosition(:,1) - CellPosition(i,1)) * 10^3; %Convert to nm
        Y = abs(CurrentCellPosition(:,2) - CellPosition(i,2)) * 10^3;
        Z = abs(CurrentCellPosition(:,3) - CellPosition(i,3)) * 10^3;
    
         if (CellPosition(i,1) <= X < CellRadius) | (CellPosition(i,1) <= X < NucleusRadius) &...
                  (CellPosition(i,2) <= Y < CellRadius) | (CellPosition(i,2) <= Y < NucleusRadius) & ...
                            (CellPosition(i,3) <= Z < CellRadius) | (CellPosition(i,3) <= Z < NucleusRadius);
      
                   Ionisations{i}(j,:) = Damage(j,:)
         else
                   continue
         end
     end
end

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dpb 2020-3-14

Attach .mat file w/ small(ish) set of the data to observe/test...w/ desired results.

mel1708 2020-3-14

在 MATLAB Online 中打开

I cut Damage down from 1753x3 to 201x3. I also took out the data that isn't needed for this part so the first line in the double for loop just has to be

CurrentCellPosition = cell2mat(Damage(:,:));

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Answer 1

Ameer Hamza 2020-3-15

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在 MATLAB Online 中打开

You don't need the inner for loop. Following code shows how you can do it using vectorized operations

CellRadius = 1 * 10^4; %nm
NucleusRadius = 7 * 10^3; %nm
NumberofCells = size(CellPosition,1);
CurrentCellPosition = cell2mat(Damage);
for i = 1:NumberofCells
    CellPosition_row = CellPosition(i, :);
    error = (CurrentCellPosition - CellPosition_row)*1000;
    
    X_err = error(:,1);
    Y_err = error(:,2);
    Z_err = error(:,3);
    
    mask = (X_err < CellRadius | X_err < NucleusRadius) & ...
        (Y_err < CellRadius | Y_err < NucleusRadius) & ...
        (Z_err < CellRadius | Z_err < NucleusRadius); % correct the condition if it is wrong
    
    Ionisations{i} = CurrentCellPosition(mask, :);
end