""Unrecognized variable name 'Time'" I am getting this type of error during ploting , how I can fix this?

Warning: Variable names were modified to make them valid MATLAB identifiers. The original names are saved in the VariableDescriptions

property.

Error using check (line 12)

Unrecognized variable name 'Time'.

data_files_nr_mai = ls('*.csv');%list

const = 71.940; %upper_pyranometer_constant

%for jj = 1 : size(data_files_nr_mai,1);

data = readtable('KLOG0024.CSV');

time = data(:,{'Time'});

uper_p = data(:,{'Pyrn1_Avg'});

a = table2array(uper_p);

b = a .* const;

%for jj = 1 : size(data_files_nr_mai,1);

figure

%subplot(7,4,jj)

plot(time{:,:},b);

%plot(a,b);

Answer 1

[Jeffrey Clark]

@Ritesh, if you remove the first 2 header lines from the CSV it will work properly. There is probably an alternative to have MATLAB skip the first two lines but you would have to search the heirarcy of help for Create table from file - MATLAB readtable (mathworks.com) to see what options are needed to do so.

[Ritesh]

Thanks @Jeffrey Clark, but I have a question that....why in hundred of file some of the file showing date coloumn as a string and rest are working good with same code?

[Jeffrey Clark]

@Ritesh if you will post one that works with your original code I may be able to tell you.

[Ritesh]

this one work with my code

Answer 2

[Stephen23]

The files are formatted slightly differently, as these screenshots show:

The READTABLE() documentation gives some options that specify the header size or data location, e.g.:

opt = {'VariableNamesLine',3, 'NumHeaderLines',2};
t08 = readtable('KLOG0008.csv', opt{:})

t08 = 1440×9 table
       Date         Time      STemp_Avg    Pyrn1_Avg    Pyrn2_Avg    Pyrg1_Avg    Pyrg2_Avg    ATM_Press_Avg    Tacho_Avg
    __________    ________    _________    _________    _________    _________    _________    _____________    _________

    21.12.2018    00:00:00      611.7        0.152        0.014        -0.24       -0.018          98539         1774.9  
    21.12.2018    00:01:00     611.77        0.145        0.013        -0.24       -0.018          98541         1763.7  
    21.12.2018    00:02:00     611.98        0.146        0.013       -0.244       -0.018          98540         1765.1  
    21.12.2018    00:03:00     612.43        0.151        0.014       -0.249       -0.019          98541         1764.2  
    21.12.2018    00:04:00     612.88        0.153        0.015       -0.252        -0.02          98540         1762.8  
    21.12.2018    00:05:00      613.1        0.152        0.013       -0.251       -0.022          98538         1760.4  
    21.12.2018    00:06:00     613.14        0.151        0.012       -0.249       -0.025          98537           1778  
    21.12.2018    00:07:00     613.01        0.152        0.011       -0.248       -0.023          98542         1767.4  
    21.12.2018    00:08:00     612.99        0.155        0.011       -0.247       -0.023          98542         1777.4  
    21.12.2018    00:09:00     612.98        0.154        0.012       -0.246       -0.021          98547         1760.9  
    21.12.2018    00:10:00      612.9        0.149        0.011       -0.243       -0.024          98548         1758.8  
    21.12.2018    00:11:00     612.39        0.144        0.007       -0.239       -0.023          98548         1765.1  
    21.12.2018    00:12:00     611.96        0.146        0.009       -0.237       -0.021          98549           1758  
    21.12.2018    00:13:00      611.8        0.153        0.011       -0.239        -0.02          98553         1773.9  
    21.12.2018    00:14:00        612        0.162        0.015       -0.244       -0.019          98557           1775  
    21.12.2018    00:15:00     611.93        0.166        0.015       -0.248       -0.023          98553         1780.1  

t24 = readtable('KLOG0024.csv', opt{:})

t24 = 1440×9 table
       Date         Time      STemp_Avg    Pyrn1_Avg    Pyrn2_Avg    Pyrg1_Avg    Pyrg2_Avg    ATM_Press_Avg    Tacho_Avg
    __________    ________    _________    _________    _________    _________    _________    _____________    _________

    06.01.2019    00:00:00     570.25        0.349        0.054       -0.906       -0.113          96863         1768.7  
    06.01.2019    00:01:00     570.24         0.35        0.055       -0.905       -0.112          96862         1765.8  
    06.01.2019    00:02:00     570.26        0.353        0.057       -0.904        -0.11          96861         1770.3  
    06.01.2019    00:03:00     570.26        0.356        0.058       -0.904       -0.112          96863         1769.1  
    06.01.2019    00:04:00     570.24        0.356        0.055       -0.905       -0.114          96865         1762.1  
    06.01.2019    00:05:00      569.8        0.357        0.055       -0.903       -0.112          96864         1770.6  
    06.01.2019    00:06:00     569.65        0.358        0.055       -0.903       -0.111          96867         1770.8  
    06.01.2019    00:07:00     569.27         0.36        0.055       -0.901       -0.112          96867         1769.1  
    06.01.2019    00:08:00     568.77         0.36        0.054         -0.9        -0.11          96867         1758.5  
    06.01.2019    00:09:00     568.43        0.362        0.056       -0.899        -0.11          96867         1773.2  
    06.01.2019    00:10:00     567.93        0.363        0.055       -0.899       -0.109          96868         1770.6  
    06.01.2019    00:11:00     567.82        0.366        0.057       -0.898       -0.108          96868         1754.5  
    06.01.2019    00:12:00     568.15         0.37         0.06       -0.899       -0.107          96867           1773  
    06.01.2019    00:13:00     568.46        0.372        0.061       -0.899       -0.108          96867         1763.3  
    06.01.2019    00:14:00     568.89        0.373         0.06       -0.899        -0.11          96867         1763.9  
    06.01.2019    00:15:00     568.93        0.374        0.059       -0.899       -0.109          96868         1769.3  

[Ritesh]

Thanks@Stephen23