I need to format a text file

3 views (last 30 days)
Duane Melvin
Duane Melvin on 24 May 2022
Commented: Voss on 25 May 2022
0.6876 1 0CF02A83x Rx d 8 13 7D 00 7D 29 7D C0 FF
0.6882 1 0CFFD183x Rx d 8 1C DE 8F FE FA BD 8A 42
0.6976 1 0CF02A83x Rx d 8 0B 7D 08 7D 2F 7D C0 FF
0.6982 1 0CFFD183x Rx d 8 2B DE CF FB FA E1 8A 42
0.7076 1 0CF02A83x Rx d 8 FD 7C 0D 7D 29 7D C0 FF
0.7082 1 0CFFD183x Rx d 8 3C DE 8F FC FA AD 8A 42
0.7176 1 0CF02A83x Rx d 8 F9 7C 15 7D 25 7D C0 FF
0.7182 1 0CFFD183x Rx d 8 48 DE 2F FE FA 55 8A 42
This is a .txt file with potentially 500000 rows, only 8 are displayed for my question
I want to write a Matlab script to perform these 5 steps on the .txt file above:
1) remove every row that contains F02A
2) remove these items from the remaining rows 1 0CFFD183x Rx d 8 leaving only the 8 HEX values
3) keep only the first two bytes of the HEX values as in rows 2, 4, 6, 8, want to have only 1C DE remaining
example:
1C DE
2B DE
3C DE
48 DE
5) last step is to convert to Decimal, then perform this math
example for row one (DE*256)+1C)/DE or ((222*256)+28)/222 =
example for row two (DE*256)+2B)/DE or ((222*256)+43)/222 =
which produces this for first and second rows above etc
256.1261
256.1936
.
.
.
Thanks for answering

Accepted Answer

Voss
Voss on 24 May 2022
It's not clear whether you need any of those intermediate results or just the final result, but here's one way to do everything:
fid = fopen('test.txt');
data = fread(fid,'*char').';
fclose(fid);
% Steps 1-3
hex_data = regexp(strsplit(data,newline()), ...
'([0-9A-F]+)x\>.*?(\<[0-9A-F]{2}\>)\s(\<[0-9A-F]{2}\>)', ...
'tokens','once');
hex_data = vertcat(hex_data{:})
hex_data = 8×3 cell array
{'0CF02A83'} {'13'} {'7D'} {'0CFFD183'} {'1C'} {'DE'} {'0CF02A83'} {'0B'} {'7D'} {'0CFFD183'} {'2B'} {'DE'} {'0CF02A83'} {'FD'} {'7C'} {'0CFFD183'} {'3C'} {'DE'} {'0CF02A83'} {'F9'} {'7C'} {'0CFFD183'} {'48'} {'DE'}
hex_data(contains(hex_data(:,1),'F02A'),:) = []
hex_data = 4×3 cell array
{'0CFFD183'} {'1C'} {'DE'} {'0CFFD183'} {'2B'} {'DE'} {'0CFFD183'} {'3C'} {'DE'} {'0CFFD183'} {'48'} {'DE'}
% Step 5
result = hex2dec(strcat(hex_data(:,3),hex_data(:,2)))./hex2dec(hex_data(:,3));
disp(result);
256.1261 256.1937 256.2703 256.3243
  4 Comments
Duane Melvin
Duane Melvin on 25 May 2022
thanks so much it is now functional

Sign in to comment.

More Answers (0)

Categories

Find more on Large Files and Big Data in Help Center and File Exchange

Products

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!