how to add and sort a cell with a string in a cell array in order to replace or add a cell with respect the last word of the cell?

I did this using a lot of lines and I was wondering if you could recommend me a better way to do it.

I have a predefined cell array and I'm constantly generating new data that I have to add or replace in the cell array and sorted regarding the last word of the cell.

Let's say I have a cell array A like:

 A{1, 1} = 'whatever - a';
 A{2, 1} = 'doesNotMatter - b';
 A{3, 1} = 'not even with spaces - d';
 A{4, 1} = 'blablabla - ee';

if I have these new cells to add in my array

 newCell1 = 'thanksForHelping - c';
 newCell2 = 'I really appreciate it - ee';

I would like to add newCell1 (since "c" is not in the original) and replace newCell2 with the one in A{4, 1} (since "ee" is there)

so at the end, I can obtain something like:

 A   = 

 5×1 cell array

 'whatever - a'
 'doesNotMatter - b'
 'thanksForHelping - c'
 'not even with spaces - d'
 'I really appreciate it - ee'

I know that the ideal thing will be to change the data to "a - whatever" and use a simple sort but it is not possible to change the final format.

Could you recommend me something?

Thanks!

Answer 1

[the cyclist]

% The data
A{1, 1} = 'whatever - a';
A{2, 1} = 'doesNotMatter - b';
A{3, 1} = 'not even with spaces - d';
A{4, 1} = 'blablabla - ee';

newCell{1,1} = 'thanksForHelping - c';
newCell{2,1} = 'I really appreciate it - ee';

% Find last words in the old and new data
hyphenIndexA = regexp(A,'-');
lastWordA = cellfun(@(x,y)x(y+2:end),A,hyphenIndexA,'UniformOutput',false);

hyphenIndexNew = regexp(newCell,'-');
lastWordNew = cellfun(@(x,y)x(y+2:end),newCell,hyphenIndexNew,'UniformOutput',false);

% Swap in the replacements if they exist
[tfReplace,locationIndexReplace] = ismember(lastWordA,lastWordNew);
A(tfReplace) = newCell(locationIndexReplace(tfReplace));

% Append the new to the old, if they do not exist
[tfAdd,locationIndexAdd] = ismember(lastWordNew,lastWordA);
A = [A; newCell(not(tfAdd))]

[German Preciat Gonzalez]

Cool, thanks man!

It is very efficient. However, the last two lines do not sort the array

[tfAdd,locationIndexAdd] = ismember(lastWordNew,lastWordA)

tfAdd =

2×1 logical array

   0
   1

locationIndexAdd =

     0
     4

A =

5×1 cell array

    'whatever - a'
    'doesNotMatter - b'
    'not even with spaces - d'
    'I really appreciate it - ee'
    'thanksForHelping - c'

The last line should be in the middle. Do you know how can I fix it?

Thanks!

[the cyclist]

[sortedLastWordA,sortingIndex] = sort(lastWordA);
A = A(sortingIndex);

[the cyclist]

Be sure to do that step after you've got the new elements and replacements in there.

There might be a more efficient way to combine some of those steps, I suppose. But better to understand the whole algorithm first.