counting the number of values in table if the condition satisfies??

Hi,

I have 2 tables as

a =

y=

If the string in "y" matches with string in ''a'' i want to count all the strings after matching the strings.

I am looking for looping only not like count command.

Thanks in advance

[madhan ravi]

Why are you looking for a loop ?

[KSSV]

Read about Strcmp, contains, ismember.

[Haritha]

i want to use for some server data looping only its possible to work for me. Please help me on this if you know

[madhan ravi]

Could you attach a sample of you data as .mat file and your desired output?

[dpb]

" data looping only its possible to work for me"

Can you explain why this is so...maybe there's a solution to that.

I'd suggest the data look as though would be more easily dealt with as categorical rather than cellstr or if must for some other reason keep as character, use the new(ish) string() class which allows much easier manipulation (such as the "==" operator for one).

[Haritha]

I am attaching sample code here. If string matches.i want to count from 'moble' to 'end' of the table. Let me know if you have any idea on this

xx = table({'computer'; 'car'; 'mobile'; 'bus'; 'tree'; 'jeep'});
U=table({'car'});
A=zeros(1,numel(U));
count=1;
for i=1:numel(xx)
  a = xx(i,1);
  for j=1:numel(U)
     b = U(j,1);
     c = strcmp(xx.Var1,U.Var1);
     if c==1
       %A{i}=A{i}+1; 
       count= count+xx.Var(c+1:end,:)
    end
  end
end

[Guillaume]

Your screenshot doesn't look like the way matlab displays tables in the variable editor. So we're left with the question: do you actually have tables or something else?

And if y is indeed a table, does it have only one row and one column? If so, why is it a table?

So, as madhan asked, attach your actually data as a mat file rather than giving us screenshot that don't describe your data properly.

What does matching after the strings mean? Where does after starts and ends. Presumably you mean the columns after the match on th same row? Is the match to be found in any column, or just the first one?

What does counting actually mean? If the match is to be found in the first column, then the count of strings in the other column is always 2.

[Haritha]

I have attached sample code. If string in U matches with string in xx I want to count the strings after matching string in xx. I have only one column as xx

[Guillaume]

Why is U a table as opposed to the simpler

U = 'car';

?

Why is xx a table as opposed to simply a cell array?

You don't seem to know how to index cell arrays, tables or matrices. If A is matrix, A{i} is an error.

So in your example, is the desired result 4? (4 strings after 'car')

Answer 1

[dpb]

xx = categorical({'computer'; 'car'; 'mobile'; 'bus'; 'tree'; 'jeep'});
u='car';
[ia,ib]=ismember(u,xx);
if ia
  count=numel(xx)-2+1;      % inclusive count
else
  count=nan;                % not found indicator
end

tables unnecessarily complicate life when they really have no useful reason for using them in a given case.

Using categorical for such variables simplilfies comparisons greatly; that's what they're for.

Above for a one-at-a-time lookup, loop over an array of u if needed...

[Haritha]

Ok Finally i will change it to cell array then i will use this other than table matching cells matching is fine

[Guillaume]

That count line should be:

count = numel(XX) - in + 1;

However, you could just replace the whole lot by:

count = numel(XX) - find(u == XX, 1);

In the above case, there's no benefit to using categorical. You could just stick to a cell array, in which case you replace the == by strcmp