CSV readtable dosen't work

Hi there,

I am trying to read a CSV file with readtable. Readtable doesn't detect the correct datatype and detectImportOptions also dosen`t work either. I tried to convert the last columns to numbers with the following loop:

for i = 11:(width(stgsa_csv_table))
    stgsa_csv_table{:,i} = str2double(stgsa_csv_table{:,i});
end

But it's not possible and following error message is displayed :

Error using {}

Conversion to cell from double is not possible.

Does anyone know how to solve this problem?

Thanks Dominik

[Stephen23]

"Does anyone know how to solve this problem?"

Probably by fixing the READTABLE options you are using, rather than fiddling around converting text to numeric.

Please upload a sample data file by clicking the paperclip button.

[Dominik Coenen]

Sure, I added the sample data.

[Stephen23]

F = '02.08.23_15.54.32_RTCM_STA8100_D0_stgsa.csv';
T = readtable(F, 'Delimiter',',', 'ExpectedNumVariables',26, 'VariableNamesLine',1)

T = 4475×13 table
       tow        gnss_id    mode    fix_mode    band_mask    hdop    vdop    pdop    sync    sat_mask     sat01    sat02    sat03
    __________    _______    ____    ________    _________    ____    ____    ____    ____    _________    _____    _____    _____

    3.0929e+05       0        1         3            1        2.9     2.7      4       1          4e+07       2        3       31 
    3.0929e+05       2        1         3            1        2.9     2.7      4       1              0     NaN      NaN      NaN 
    3.0929e+05       3        1         3            1        2.9     2.7      4       1              0     NaN      NaN      NaN 
    3.0929e+05       7        1         3            1        2.9     2.7      4       1      8.002e+08      22       36      NaN 
    3.0929e+05      13        1         3            1        2.9     2.7      4       0             20      46      NaN      NaN 
    3.0929e+05       0        1         3            1        2.9     2.7      4       1          4e+07       2        3       31 
    3.0929e+05       2        1         3            1        2.9     2.7      4       1              0     NaN      NaN      NaN 
    3.0929e+05       3        1         3            1        2.9     2.7      4       1              0     NaN      NaN      NaN 
    3.0929e+05       7        1         3            1        2.9     2.7      4       1      8.002e+08      22       36      NaN 
    3.0929e+05      13        1         3            1        2.9     2.7      4       0             20      46      NaN      NaN 
    3.0929e+05       0        1         3            1        2.9     2.7      4       1          4e+07       2        3       31 
    3.0929e+05       2        1         3            1        2.9     2.7      4       1              0     NaN      NaN      NaN 
    3.0929e+05       3        1         3            1        2.9     2.7      4       1              0     NaN      NaN      NaN 
    3.0929e+05       7        1         3            1        2.9     2.7      4       1      8.002e+08      22       36      NaN 
    3.0929e+05      13        1         3            1        2.9     2.7      4       0             20      46      NaN      NaN 
    3.0929e+05       0        1         3            1        2.9     2.7      4       1          4e+07       2        3       31 

[Dominik Coenen]

That's weird. The same line of code gives me a different result and data types are not recognized.

Answer 1

[Star Strider]

Perhaps something like this —

T1 = cell2table(compose('%f',randn(5,7)))

T1 = 5×7 table
        Var1             Var2             Var3             Var4             Var5             Var6             Var7     
    _____________    _____________    _____________    _____________    _____________    _____________    _____________

    {'0.737553' }    {'0.737513' }    {'-0.122106'}    {'1.469730' }    {'-0.879202'}    {'1.394899' }    {'-0.660295'}
    {'2.355983' }    {'0.407245' }    {'1.367768' }    {'1.489333' }    {'-1.308921'}    {'0.754867' }    {'-0.736306'}
    {'1.689538' }    {'2.381704' }    {'-0.961434'}    {'-0.736418'}    {'-0.119951'}    {'0.653452' }    {'-0.209794'}
    {'0.473317' }    {'-0.035799'}    {'-0.680802'}    {'1.090041' }    {'-0.158576'}    {'-1.444836'}    {'-1.575928'}
    {'-0.430204'}    {'1.775675' }    {'2.057153' }    {'0.120885' }    {'0.270623' }    {'-0.592076'}    {'-1.926796'}

VN = T1.Properties.VariableNames;
T2 = varfun(@str2double,T1);
T2.Properties.VariableNames = VN

T2 = 5×7 table
     Var1        Var2         Var3        Var4        Var5        Var6        Var7  
    _______    _________    ________    ________    ________    ________    ________

    0.73755      0.73751    -0.12211      1.4697     -0.8792      1.3949    -0.66029
      2.356      0.40725      1.3678      1.4893     -1.3089     0.75487    -0.73631
     1.6895       2.3817    -0.96143    -0.73642    -0.11995     0.65345    -0.20979
    0.47332    -0.035799     -0.6808        1.09    -0.15858     -1.4448     -1.5759
    -0.4302       1.7757      2.0572     0.12089     0.27062    -0.59208     -1.9268

.

[Dominik Coenen]

Thanks. This works.

In my case one column is a hex number. Is it possible to convert this certain column to hex?

[Star Strider]

As always, my pleasure!

One approach (consistent with the current approach) —

T1 = cell2table(compose('%f',randn(5,7)));
T1.HexVar = {'8';'9';'A';'B';'C'}

T1 = 5×8 table
        Var1             Var2             Var3             Var4             Var5             Var6             Var7         HexVar
    _____________    _____________    _____________    _____________    _____________    _____________    _____________    ______

    {'0.307080' }    {'1.332698' }    {'0.452805' }    {'0.763319' }    {'-1.798578'}    {'1.854305' }    {'-0.486706'}    {'8'} 
    {'-1.020499'}    {'1.740624' }    {'-0.198948'}    {'0.244900' }    {'0.116841' }    {'-0.539302'}    {'-0.093323'}    {'9'} 
    {'-2.086324'}    {'0.330824' }    {'-2.041314'}    {'-0.064818'}    {'0.020421' }    {'2.119804' }    {'0.276070' }    {'A'} 
    {'0.407898' }    {'-1.075031'}    {'0.652554' }    {'-0.965714'}    {'-1.015894'}    {'-1.602972'}    {'1.615435' }    {'B'} 
    {'-0.175186'}    {'2.857849' }    {'-0.991484'}    {'1.188328' }    {'1.524303' }    {'-0.039499'}    {'-0.034836'}    {'C'} 

VN = T1.Properties.VariableNames;
T1.HexVar = compose('%f',hex2dec(T1.HexVar))

T1 = 5×8 table
        Var1             Var2             Var3             Var4             Var5             Var6             Var7            HexVar    
    _____________    _____________    _____________    _____________    _____________    _____________    _____________    _____________

    {'0.307080' }    {'1.332698' }    {'0.452805' }    {'0.763319' }    {'-1.798578'}    {'1.854305' }    {'-0.486706'}    {'8.000000' }
    {'-1.020499'}    {'1.740624' }    {'-0.198948'}    {'0.244900' }    {'0.116841' }    {'-0.539302'}    {'-0.093323'}    {'9.000000' }
    {'-2.086324'}    {'0.330824' }    {'-2.041314'}    {'-0.064818'}    {'0.020421' }    {'2.119804' }    {'0.276070' }    {'10.000000'}
    {'0.407898' }    {'-1.075031'}    {'0.652554' }    {'-0.965714'}    {'-1.015894'}    {'-1.602972'}    {'1.615435' }    {'11.000000'}
    {'-0.175186'}    {'2.857849' }    {'-0.991484'}    {'1.188328' }    {'1.524303' }    {'-0.039499'}    {'-0.034836'}    {'12.000000'}

T2 = varfun(@str2double,T1);

T2.Properties.VariableNames = VN

T2 = 5×8 table
      Var1       Var2        Var3        Var4         Var5        Var6         Var7       HexVar
    ________    _______    ________    _________    ________    _________    _________    ______

     0.30708     1.3327     0.45281      0.76332     -1.7986       1.8543     -0.48671       8  
     -1.0205     1.7406    -0.19895       0.2449     0.11684      -0.5393    -0.093323       9  
     -2.0863    0.33082     -2.0413    -0.064818    0.020421       2.1198      0.27607      10  
      0.4079     -1.075     0.65255     -0.96571     -1.0159       -1.603       1.6154      11  
    -0.17519     2.8578    -0.99148       1.1883      1.5243    -0.039499    -0.034836      12  

This requires knowing what variables are hex and specifically converting them to numeric first. The detectImportOptions documentation under Parameters for Text Files Only has HexType that governs how to convert it. I get the impression that the converstion to numeric is done automatically, although selecting 'text' woiuld prevent its conversion so it would be read into the table as text.

.