Scan a data file for data after keywords

Hello everyone,

I have an output file from a simulation which is not ordered in a specific way and changes depending on the simulation result.

Somewhere in the file, sections like this can be found. They are on the other hand always the same:

Seed number 1 set at time t = 5.00000E-08 s

-------------------------------------------

in the bulk, zp = 51971

Phase: 1 (BCC_A2)

Seed type: 1 (7: 3/19)

Local temperature = 1308.5 K

Undercooling = 445.98 K

Nucleus curvature undercooling = 0.99588 K

Grain number = 76

What I wanted to ask as a MATLAB beginner: How can I search for keywords like "Seed number", "t =", "zp =" and "Undercooling=" and get the values behind them and write them all in a list with 4 columns and the values which belong together in every line.

I suspect that very similar questions have already answered in this forum. However, I was not able to understand how the solutions are supposed to work. I would be very grateful for any help.

Best regards

Moritz

Answer 1

[DGM]

I'm sure there are better ways of doing this, but this is one way.

alltext = fileread('testfile.txt');
alltext = split(alltext,newline);

% find numbers
% this only looks for a block of non-whitespace after each prefix
% if you want to be more explicit, you can replace
% [^\s]+ (one or more non-whitespace characters
% with [+-\.\dE]+ (one or more of the characters +-.E or any digit)
% each output is a cell array with one row per line (mostly empty cells)
seednum = regexp(alltext,'(?<=Seed number\s*)[^\s]+','match');
t = regexp(alltext,'(?<=time t =\s*)[^\s]+','match');
zp = regexp(alltext,'(?<=bulk, zp =\s*)[^\s]+','match');
uc = regexp(alltext,'(?<=Undercooling =\s*)[^\s]+','match');

% concatenate
D = [seednum t zp uc];

% this converts cellchar to numeric and implicitly omits empty cells
% this will break if there aren't the same number of matches per column
D = cell2mat(cellfun(@str2double,D,'uniform',false))

D = 4×4

1.0e+04 * 0.0001 0.0000 5.1971 0.0446 0.0001 0.0000 5.1971 0.0446 0.0001 0.0000 5.1971 0.0446 0.0001 0.0000 5.1971 0.0446

[Moritz Schäfle]

Hi DGM,

I can not say how thankful I am for this. Thank you very much not only for this solution, but for the explanation!

This helped me a great way. I wish you all the best.

Moritz

[DGM]

Glad to hear that. If and when you find that it satisfies your question, you can click "accept" so that it gets moved to the "accepted" queue, hopefully making it more likely to help future readers with a similar question.