I want to read only the numbers from the text file between a range ( were the start and end differs constantly from one txt file to another)

I want to read only the numbers from a txt file ( attached) by skipping the first few lines which are not needed till the end of the file(always skipping the last two lines)

for example

We read the first letter of every line in the file.

if the line starts with an alphabet i want it to be skipped and read it when it has a number as it's first letter.

So that eventually i will automatically get the range of the lines i want ,( from were the values start and end) automatically.

[Geoff Hayes]

Vinnit - there is no text file attached to your question.

It sounds like you just want to read each line in the file and "do something" with those lines that begin with a number. The links for fopen and fgetl should get you started.

[dpb]

Or, simply read the full file in as text and eliminate the lines unwanted in memory. May well be faster overall than fgetl reading/parsing line-by-line.

file=textread('yourfile.txt','%s','delimiter','\n','whitespace','');

gives a cell array, one element/line. To eliminate the lines w/ initial alphabetic characters leaving the numeric ones,

isdigit=isstrprop(char(file),'digit'); isdigit=isdigit(:,1);
file=file(isdigit);

Used the intermediary logical array since can't use subscripting on expression results, unfortunately. Can do same operation w/ cellfun if prefer that route.

Now you can use textscan or sscanf on the remaining numeric fields.

[Vinit]

I want to delete the rows with the first character other than a number and copy the other rows which has it's first as a number into a new file.

For ex . my file looks like this

Mach-1 asrt asrj ssrj . . . 0346 1346 2346 3334 4337 . . . aaerh baer daer frah . . . 1345 2346 3436 4346 . . . asdh bsth

I only wan the lines which starts with a number

[Vinit]

I want to delete the rows with the first character other than a number and copy the other rows which has it's first as a number into a new file.

For ex . my file looks like this

Mach-1 asrt asrj ssrj . . . 0346 1346 2346 3334 4337 . . . aaerh baer daer frah . . . 1345 2346 3436 4346 . . . asdh bsth

I only wan the lines which starts with a number

[Vinit]

I have the cell with all the values thanks to you....the problem i have now... the data is like this .......0 1 2 3 0 1 2 3 0 1 2 3.. these are redings of time... how to i combine the times so that when i plot all of this will be of a same line........?

[dpb]

Me no follow -- once you have the desired lines parsed, then just convert to numeric --

v=str2num(char(file));

Now you've got a Nx3 array of the values to do whatever you wish with.

Answer 1

[dpb]

Complete comments in one place...

Or, simply read the full file in as text and eliminate the lines unwanted in memory. May well be faster overall than fgetl reading/parsing line-by-line.

file=textread('yourfile.txt','%s','delimiter','\n','whitespace','');

gives a cell array, one element/line. To eliminate the lines w/ initial alphabetic characters leaving the numeric ones,

isdigit=isstrprop(char(file),'digit'); isdigit=isdigit(:,1);
file=file(isdigit);

Used the intermediary logical array since can't use subscripting on expression results, unfortunately. Can do same operation w/ cellfun if prefer that route.

v=str2num(char(file));

Now you've got a Nx3 array of the values to do whatever you wish with.