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

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Haritha 2019-3-27

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评论： Guillaume 2019-3-28

采纳的回答： dpb

Hi,

I have 2 tables as

a =

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

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Haritha 2019-3-27

编辑：Haritha 2019-3-27

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 2019-3-27

编辑：Guillaume 2019-3-27

在 MATLAB Online 中打开

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')

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dpb 2019-3-27

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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...

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Haritha 2019-3-28

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

Guillaume 2019-3-28

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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

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