need help reading only the numeric data in a value that contains letters

Hello,

I am trying to read in a text file where some numeric values contain letters at the end. Example text file:

487X 445X 599X 622
484  535X 568X 702E

I would like my resulting variable to only contain numbers:

myvar = [487 445 599 622;484 535 568 702];

Using the importdata command with a different file with the same type of text as the example provided above worked fine:

myfile = dir('*.txt');
mydata = importdata(myfile(1,1).name);

Can anyone tell me why this works for some files and not others and does anyone have a suggested solution?

Thanks, Dan

Answer 1

[Jan]

Another approach:

fid = fopen('test.txt', 'r');
if fid == -1, error('Cannot open file'); end
S = fread(fid, [1, inf], '*char');
fclose(fid);
S(S > '9') = ' ';
D = reshape(sscanf(S, '%g'), [], 4);

[Walter Roberson]

I believe you need to transpose before the reshape, as sscanf reads across the columns but reshape works down columns.

Answer 2

[Fangjun Jiang]

fid=fopen('test.txt','rt');
a=textscan(fid,'%s');
b=regexp(a{1},'\d*','match');
c=cellfun(@str2double,b);
d=reshape(c,[],4)
fclose(fid);

d =
   487   599   484   568
   445   622   535   702

Answer 3

[Walter Roberson]

NumPerLine = 4;
fid = fopen(myufile(1).name,'rt');
indata = textscan(fid, repmat('%f%*c',1,NumPerLine), 'CollectOutput',1);
fclose(fid);
mydata = indata{1};

I believe this should work even in the case where the last character on the line is a digit with no letter following before the end of line.

Answer 4

[Dan]

Thanks everyone for the suggestions. Jan, your approach seems to work the best and quickest for me!

Does anyone know why my other similar file has worked using importdata?

Answer 5

[Walter Roberson]

transtab = blanks(256);
transtab('0':'9') = '0':'9';

D = reshape( sscanf(transtab(fileread('test.txt')), '%g'), 4, []) .';