Matlab - string containing a number and equal sign - matlab

Question

I have a data file that contains parameter names and values with an equal sign in between them. It's like this:
A = 1234
B = 1353.335
C =
D = 1
There is always one space before and after the equal sign. The problem is some variables don't have values assigned to them like "C" above and I need to weed them out.
I want to read the data file (text) into a cell and just remove the lines with those invalid statements or just create a new data file without them.
Whichever is easier, but I will eventually read the file into a cell with textscan command.
The values (numbers) will be treated as double precision.
Please, help.
Thank you,
Eric

Answer 1

Try this:
fid = fopen('file.txt'); %// open file
x = textscan(fid, '%s', 'delimiter', '\n'); %// or '\r'. Read each line into a cell
fclose(fid); %// close file
x = x{1}; %// each cell of x contains a line of the file
ind = ~cellfun(#isempty, regexp(x, '=\s[\d\.]+$')); %// desired lines: space, numbers, end
x = x(ind); %// keep only those lines

Answer 2

If you just want to get the variables, and reject lines that do not have any character, this might work (the data.txt is just a txt generated by the example of data you have given):
fid = fopen('data.txt');
tline = fgets(fid);
while ischar(tline)
tmp = cell2mat(regexp(tline,'\=(.*)','match'));
b=str2double(tmp(2:end));
if ~isnan(b)
disp(b)
end
tline = fgets(fid);
end
fclose(fid);
I am reading the txt file line by line, and using general expressions to get rid of useless chars, and then converting to double the value read.