want to skip the text lines in a file

I have a text file in which first few lines are text. after than the numeric data is there. I want to skip the text lines.The number of text line is also not fixed. But data always start after the string "BEGIN DATA". I have tried but I am not getting any way to read the numeric data ignoring the text lines. my data file looks like

"gdeudfghdjcklkscdjdjljmdxsjdjmjmdjdckdckshfihsklkdkshncfsdjgbfsdgfvdefhvdfjcs

klhnfcjksdzhbsfvbhdslhfc.siafslfkdl;s

hfcsddjkhfcsjldifgdsfgdrjlsjfkldjksdfgvjdsgvbjdshngffgksl

dsghbfvdjkshghrjgujskdhna,h
BEGIN DATA

1

5

2

3

6

74

5

8

6

.

.

I need only

1

5

2

3

6

74

5

8

6

.

.

in a double

Thanks in advance

Answer 1

[Andrei Bobrov]

f1 = fopen('test2.txt'); % your data in file test2.txt
c = textscan(f1,'%s','Delimiter','\n');
fclose(f1);

out = str2double(c{1}(find(strcmp(c{1},'BEGIN DATA'))+1:end));
out = out(~isnan(out));

or

out = regexp(c{1},'^\d*$','match');
out = str2double(cat(1,out{~cellfun(@isempty,out)}));

or

out = str2double(c{1}(cellfun(@(y)all(~isletter(y))&~isempty(y),c{1})));

[Moon Datta]

I want to take file name i.e.,test2.txt as a input. But then it is not working.

what to do now?

[Andrei Bobrov]

corrected

[Moon Datta]

I am not understanding what is corrected. actually I need in this way

It will ask me to give the input

I shall give the input

then the program will run

it will give me result

[SYED AZHAR]

Go for Gui Interfacing

Answer 2

[Jan]

Alternatively:

DataStr = fileread('test2.txt');
Key     = 'BEGIN DATA';
Index   = strfind(DataStr, Key);
Value   = sscanf(DataStr(Index + length(Key) + 1), '%g ');