There may be a way to do that in one single pass, but for me these kind of problems are easier to sort with a 2 pass approach.
- Pass 1: Read all the columns with a constant format according to their type (string, integer, etc ...) and read the non constant part in a separate column which will be processed in second pass.
- Pass 2: Process your irregular column according to its specificities.
In a case with your sample data, it looks like this:
%% // read file
fid = fopen('Test.txt','r') ;
M = textscan( fid , 'term%d %s %*c %[^]] %*[^\n]' ) ;
fclose(fid) ;
%% // dispatch data into variables
name = M{1,1} ;
time = M{1,2} ;
data = cellfun( @(s) textscan(s,'%f',Inf,'Delimiter',',') , M{1,3} ) ;
What happened:
The first textscan instruction reads the full file. In the format specifier:
term%d read the integer after the literal expression 'term'.%s read a string representing the date.%*c ignore one character (to ignore the character '[').%[^]] read everything (as a string) until it finds the character ']'.%*[^\n] ignore everything until the next newline ('\n') character. (to not capture the last ']'.
After that, the first 2 columns are easily dispatched into their own variable. The 3rd column of the result cell array M contains strings of different lengths containing different number of floating point number. We use cellfun in combination with another textscan to read the numbers in each cell and return a cell array containing double:
Bonus:
If you want your time to be a numeric value as well (instead of a string), use the following extension of the code:
%% // read file
fid = fopen('Test.txt','r') ;
M = textscan( fid , 'term%d %f-%f-%f-%f_%f_%f_%f %*c %[^]] %*[^\n]' ) ;
fclose(fid) ;
%% // dispatch data
name = M{1,1} ;
time_vec = cell2mat( M(1,2:7) ) ;
time_ms = M{1,8} ./ (24*3600*1000) ; %// take care of the millisecond separatly as they are not handled by "datenum"
time = datenum( time_vec ) + time_ms ;
data = cellfun( @(s) textscan(s,'%f',Inf,'Delimiter',',') , M{1,end} ) ;
This will give you an array time with a Matlab time serial number (often easier to use than strings). To show you the serial number still represent the right time:
>> datestr(time,'yyyy-mm-dd HH:MM:SS.FFF')
ans =
2015-07-31 15:58:25.612
2015-07-31 15:58:25.620
2015-07-31 15:58:25.625
