delete words from list based on logical statement

say I have a cell array x={'abatable';'abate';'abatement';'abater';'dog';'cat';'make';'abator';'see'}

and word='abatis' letter='a'

how would I delete all words from x that do not have the letter in the respective positions of the word

For example with the letter a it appears in word abatis as the 1st letter and the 3rd letter. I would then like to delete all words from x that do not have 'a' as their 1st and 3rd positions.

I have tried this

 if ismember(letter,word)
x=letter==word % returns a 1 row vector of logical statements
%.....
end

but im stuck there what else should I try.

Thanks

Answer 1

[Adam Barber]

I slightly modified Jan's answer:

List = {'abatable';'abate';'abatement';'abater';'dog';'cat'; ...
        'make';'abator';'see'}
Word = 'abatis'
C    = 'a';
pattern = (Word == C);
match   = false(1, numel(List));
for k = 1:numel(List)
  currentWord = List{k};
  lenToCheck = min(numel(pattern), numel(currentWord));
  if isequal(pattern(1:lenToCheck), currentWord(1:lenToCheck) == C)
    match(k) = true;
  end
end
List(~match) = [];

Note that I am using the smaller of the two lengths between the words. As such, "dog" and "cat" won't work, but just the word "as" would.

Of course you could modify this to make your application work.

[Max]

Is it possible to have this work for all words like dog and cat

Answer 2

[Jan]

List = {'abatable';'abate';'abatement';'abater';'dog';'cat'; ...
        'make';'abator';'see'}
Word = 'abatis'
C    = 'a';

pattern = (Word == C);
match   = false(1, numel(List));
for k = 1:numel(List)
  if isequal(pattern, (List{k} == C))
    match(k) = true;
  end
end

List(match) = [];

[EDITED, consider word with different lengths:]

...
pattern = strfind(Word, C);
match   = false(1, numel(List));
for k = 1:numel(List)
  match(k) = isequal(pattern, strfind(List{k}, C))
end
List(match) = [];

In addition I've replaced the IF branching by a direct assignment.

[Max]

When I type that in it returns List={'abatable';'abate';'abatement';'dog';'cat';'make';'see'}

[Jan]

@Max: Correct, the code considers words of the same length only. See EDITED.

Answer 3

[Thorsten]

Another way would be to use strvcat

List = {'abatable';'abate';'abatement';'abater';'dog';'cat'; ...
        'make';'abator';'see'}
Word = 'abatis'
C    = 'a';
pattern = (Word == C);

L = strvcat(List) == 'a'; n = size(L, 2);
if length(pattern) < n, pattern(n) = 0; end
P = repmat(pattern, size(L, 1), 1);
ind = ~any(abs(P - L), 2);
List = List(ind);