MATLAB: Is it possible to extract numbers from formated strings without a for cycle

stringstructvector

I have {'abc12', 'abc23', 'abc24', 'abc99'} and I need the vector [12,23,24,99]. How to do this without a for cycle?

Best Answer

Much faster than cellfun, str2double, or strrep, and with no explicit loop:

>> C = {'abc12', 'abc23', 'abc24', 'abc99'};
>> V = sscanf([C{:}],'%*3c%d')
V =
   12
   23
   24
   99
>>

Related Solutions

MATLAB: Sscanf in a cell array

Using sscanf will be faster than using str2double in a cell array:

C = {'0.001','0.34'; '89','34'; '0.898','988'};
cellfun(@(s)sscanf(s,'%f'), C)

This defines an anonymous function , which is then called by cellfun for each string in the cell array C.

EDIT: Based on Guillaume's Answer and my own tests, the fastest conversion that I could achieve (I don't have strjoin) was using array preallocation and a loop, like this:

X = nan(size(C));
for k = 1:numel(X)
    X(k) = sscanf(C{k},'%f');
end

MATLAB: Convert String (cell) table

Would this work for you?

Str={'12','12A','12B','12C','13'};
Str=strrep(Str,'A','.1');
Str=strrep(Str,'B','.2');
Str=strrep(Str,'C','.3');
Date=str2double(Str)

Best Answer

Related Solutions

MATLAB: Sscanf in a cell array

MATLAB: Convert String (cell) table

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