Reading only numeric data in a text file

I have a formatted text file (attached). I have to read it, ignoring some bits like the headings. After reading I should be able to get tx=2

ty=18

and the 4x4 matrix which is there in the text file. Rest of the strings like the headings, sensor1, chirp1 etc must be ignored.

How can I do this?

Answer 1

[Orion]

it's almays more complicated to read a file with no defined data structure.

In your case, you can use (and adjust for other files)

% read the file
fid = fopen('FrequencyShiftsV1.txt','r');
MyTextFile = textscan(fid,'%s','delimiter','\n');
fclose(fid);

MyTextFile = [MyTextFile{:}];

% get and evaluate the lines 2 and 3 (matlab expression).
eval(MyTextFile{2});
eval(MyTextFile{3});

% extract the part containg the matrix to read
MatrixLines = MyTextFile(7:end);

% get rid of Chirp1, Chirp2, ...
MatrixLines = regexprep(MatrixLines,'Chirp[^%d]','');

% Convet the char into a numerical matrix.
MyMatrix = str2num(cell2mat(MatrixLines));

[Mahi Nazir]

Brilliant thanks a lot!

Now if my text file changes to say tx=2

ty=18

N=3 and I have 3 4x4 matrices then or say if N=n, I will have n 4x4 matrices... Do I simply put a for loop? kindly help

[Orion]

if there are more lines

chirp5 ...

chirp6 ...

...

chirpN ...

it will be read and converted by the command MatrixLines = MyTextFile(7:end);

so you will get a Nx4 numerical array.

just manipulate it to create all your matrices.

if N = 12, means 3 matrices:

for i = 1 : 3
   SubMat{i} = MyMatrix(1+4*(i-1):4+4*(i-1),:);
end