MATLAB: How to filter only numerical in a table

numerical valuestable

I have data organized in a column in a table like this:

'1966.csv'
'1967.csv'
'1968.csv'
'1969.csv'
'1970.csv'
'1971.csv'
'1972.csv'
'1973.csv'
'1974.csv'
'1975.csv'

How could I only extract the numerical values (1966, 1967…) and organize them in a column beside the existing one?

Best Answer

s={'1966.csv' '1967.csv' '1968.csv' '1969.csv' '1970.csv' '1971.csv' '1972.csv' '1973.csv' '1974.csv' '1975.csv'}
out=cellfun(@(x) str2double(regexp(x,'\d+','match')),s)

Related Solutions

MATLAB: Loop to read files

To read all csv files one by one

files = dir('*.csv');
table_data = cell(1, numel(files));
for i=1:numel(files)
    filename = files(i).name;
    table_data{i} = readtable(filename);
end

To only read these specific files

range = 2010:1:2020;
table_data = cell(1, numel(range));
for i = 1:numel(range)
    filename = sprintf('data_%d.csv', range(i));
    table_data{i} = readtable(filename);
end

MATLAB: Selecting rows with maximum value with consecutive 3 days occurrence

Finding which days go together:

daygroup = cumsum([1; days(diff(datetime(Z(:, 1:3)))) > 3]);

Then, if you don't want to define a filter function:

[~, grouprow] = splitapply(@max, Z(:, 4), daygroup);
filteredZ = splitapply(@(rows, group) rows(grouprow(group(1)), :), Z, daygroup, daygroup)

If you're happy with a separate filtering function

function rows = filterrows(rows)
   [~, idx] = max(rows(:, 4));
   rows = rows(idx, :);
end

then,

filteredZ = splitapply(@filterrows, Z, daygroup)

Best Answer

Related Solutions

MATLAB: Loop to read files

MATLAB: Selecting rows with maximum value with consecutive 3 days occurrence

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