Error using cat. Dimensions of arrays being concatenated are not consistent.

Hi everybody,

i'm trying to import an ascii file in matlab and change comma with point. I'm using this code found in the community. It give me an error "Error using cat. Dimensions of arrays being concatenated are not consistent.". I should have a 7013x10139 double.

I don't know how to fix it. Any help? The file is attached here.

fid = fopen('zero_mac_cluster1.asc', 'rb');
strings = textscan(fid, '%s', 'Delimiter', '');
fclose(fid);
decimal_strings = regexprep(strings{1}, ',', '.');
data = cellfun(@str2num, decimal_strings, 'uni', 0);
zero = cat(1, data{:});
zero(zero == -9999) = NaN;

Answer 1

[Stephen23]

That is not very well designed code: the regexp is overkill, and the str2num with cellfun is likely not very efficient (as well as hiding evil eval inside...).

The code below imports the header into a structure hdr and the numeric data into matrix out (with class single to save memory):

str = fileread('zero_mac_cluster1.asc');
str = strrep(str,',','.');
% Parse Header:
opt = {'MultipleDelimsAsOne',true};
hdr = textscan(str,'%s%f',6,opt{:});
hdr = cell2struct(num2cell(hdr{2}),hdr{1});
% Parse Matrix:
opt = {'HeaderLines',numel(fieldnames(hdr)), 'CollectOutput',true};
fmt = repmat('%f32',1,hdr.ncols);
out = textscan(str,fmt,opt{:});
out = out{1};
out(out==hdr.NODATA_value) = NaN;

And checking:

>> hdr
hdr = 
           ncols: 10139
           nrows: 7013
       xllcorner: 1557267.2310345
       yllcorner: 4850030.77
        cellsize: 10
    NODATA_value: -9999
>> size(out) % matches the file rows, which is NOT what the header states!
ans =
        6065       10139
>> out(~isnan(out))
ans =
              10
            1.25
           21.75
           24.25
           22.25
            1.25
            6.25
           24.25
               0
           38.25
             7.5
            1.75
               1
            1.25
            0.25
            2.25
               7
            0.25
           36.75
             0.5
               0
            20.5
            2.75
           22.25
             4.5
             1.5
            3.25
            1.75
            0.25
               0
            1.25
             2.5
           30.25
           27.25
            2.75
               0
               1
       0.3846154
            0.75
               1
            3.75
        12.77778
           28.75
              12
               0
        3.181818
             1.5
               0
             5.5
              12
        66.92308
               0
               0
            1.75
            0.25
               0
               5
           45.75
            9.75
               0
            20.5
           24.25
               0
           19.75
            2.25
               0
               1
            23.5
               0
               0
            0.25
               1
               0
              12
        21.38889
            1.75
       0.2777778
            34.5
               8
             0.5
            0.25
           16.75
               4
               0
             -99
            2.25
             2.5
           45.25
            0.25
               0
             5.5
            2.25
            3.75
            3.75
            6.75
               0
            1.75

Note that the memory requirements are not insignificant:

>> whos out
  Name         Size                   Bytes  Class     Attributes

  out       6065x10139            245972140  single

[EM geo]

your explanation and code suit perfect for me. Good job! Thank you!!!!!