how to change decimal places after point

I have so many text files named

data_70.000_32.125
data_70.124_32.120
data_74.120_32.123

I have to make them

data_70.0_32.125
data_70.124_32.12
data_74.12_32.123

means where three zero after decimal make it one zero and remaining no zero.

[Stephen23]

Actually the names with consistent three decimal digits are better, because they:

• are easier to scan when printed in a list.
• are easier to parse (consistent formats are always better).
• sort correctly into numeric order using a standard sort. Here is an example showing that your new format does not sort correctly:

>> old = {'data_70.000_32.125.csv'; 'data_70.124_32.120.csv'; 'data_70.120_32.123.csv'};
>> sort(old) % correct numeric order
ans = 
    'data_70.000_32.125.csv'
    'data_70.120_32.123.csv'
    'data_70.124_32.120.csv'
>> new = {'data_70.0_32.125.csv'; 'data_70.124_32.120.csv'; 'data_70.12_32.123.csv'};
>> sort(new) % your format gives the wrong numeric order.
ans = 
    'data_70.0_32.125.csv'
    'data_70.124_32.120.csv'
    'data_70.12_32.123.csv'

Of course you can then use my FEX submission natsortfiles to get them back into the correct order, but why bother when those trailing zeros do the job anyway.

I don't see any good reason to remove those zeros, just disadvantages.

Answer 1

[Azzi Abdelmalek]

v={'data_70.000_32.125';'data_70.124_32.120';'data_74.120_32.123'}
w=cell(size(v))
for k=1:numel(v)
  a=regexp(v{k},'_','split')
  a2=a{2}
  a3=a{3}
  b2=str2double(regexp(a2,'\d+','match'));
  b3=str2double(regexp(a3,'\d+','match'));
  w{k}=sprintf('data_%d.%d_%d.%d',[b2 b3]);
end
celldisp(w)

[Tanmoyee Bhattacharya]

If I have so many text files How can we get the names as v in this code.How can we read all that text files to get the name.some 2000 text files are there.

[Azzi Abdelmalek]

You can use the dir command to get all your text files located somewhere

s=dir(fullfile('your_folder','*.txt'))
files={s.name}