How to open .dat file

Dear All,

I have .dat file as attached. I tried open using this script but an error.

Error using reshape

Number of elements must not change. Use [] as one of the size inputs to automatically calculate the appropriate

size for that dimension.

unzip xcat_wb.zip
fid = fopen('xcat_wb.dat','rb');
arr = fread(fid,'int8');
fclose(fid);
dim = [364,364,110];
arr = reshape(arr,dim)
volshow

Answer 1

[Sameer]

Hi @mohd akmal masud

The error occured because the total number of elements is not equal to 364 * 364 * 110

unzip('xcat_wb.zip');
fid = fopen('xcat_wb.dat', 'rb');
arr = fread(fid, 'int8');
fclose(fid);

numElements = numel(arr)

numElements = 131235840

disp(364 * 364 * 110);

    14574560

[mohd akmal masud]

So how?

[Walter Roberson]

disp(131235840 / 14574560)

    9.0044

So the actual file has a little over 8 bytes for each expected array element. That suggests that array elements are expected to be stored in double precision.

But even so, there would be parts of the file left over from [364, 364, 110] double precision elements. That suggests that either there is a substantial header (over 14 megabytes), or else that the data forms only a small portion of the file.

You need documentation as to the internal storage format of the .dat file. The file extension ".dat" is not standardized; it can refer to any random data format.

Answer 2

[mohd akmal masud]

Dear @Walter Roberson@Sameer. Solved.

unzip xcat_wb.zip
fid = fopen('xcat_wb.dat','rb');
arr = fread(fid,'int8');
fclose(fid);
dim = [384,384,890];
arr = reshape(arr,dim);
volshow(arr)