How to extract desired variables column data from a table?

I have the data in excel csv file with variable names as follows

Var1 POSValue MAXSum AVGSum SOS POS EOS Base Duration FirstHalf SecondHalf GrowthRate SenescenceRate Peaks total_cane act_y_ha act_per_ha field_yield total_FS variety

However, I want to get only required variables by using following matlab code

features = df.Properties.VariableNames(~ismember(df.Properties.VariableNames, ...

{'POS value', 'MAX sum', 'AVG sum', 'SOS', 'POS', 'EOS', ...

'base', 'duration', 'first half', 'second half', 'growth rate', ...

'senescence rate', 'peaks'}));

Instead it is extracting all the variables.

Please suggest me how to get the required variables.

Dev

Answer 1

[Mathieu NOE]

hello

this is one solution

NB that the variables names and the names your are using in the selection are not exactly the same,

like POSValue MAXSum vs POS value , MAX sum and alike....

I corrected this minor bug

T =readtable("data.xlsx");
v =   {'POSValue', 'MAXSum', 'AVGSum', 'SOS', 'POS', 'EOS', ...
    'Base', 'Duration', 'FirstHalf', 'SecondHalf', 'GrowthRate', ...
    'SenescenceRate', 'Peaks'};
v_to_use = v(ismember(v,T.Properties.VariableNames));
new_T = T(:,v_to_use)

[Devendra]

I tried it out but still it gives all 20 variables. I am attaching input file and request you to kindly check it on this file. Thanks a lot for your kind help.

[Mathieu NOE]

here you are

force readtable to use the variable name exactly as they appear in the file (with argument : 'VariableNamingRule','preserve')

T =readtable("input_file.csv",'VariableNamingRule','preserve');
% POS value	MAX sum	AVG sum	SOS	POS	EOS	Base	Duration	First half	Second half	Growth rate	Senescence rate	Peaks	total_cane	act_y_ha	act_per_ha	field_yield	total_FS	variety

v =    {'POS value', 'MAX sum', 'AVG sum', 'SOS', 'POS', 'EOS', ...
    'Base', 'Duration', 'First half', 'Second half', 'Growth rate', ...
    'Senescence rate', 'Peaks'};
v_to_use = v(ismember(v,T.Properties.VariableNames));
new_T = T(:,v_to_use)

new_T = 9×13 table
    POS value    MAX sum    AVG sum    SOS     POS    EOS     Base     Duration    First half    Second half    Growth rate    Senescence rate    Peaks
    _________    _______    _______    ____    ___    ___    ______    ________    __________    ___________    ___________    _______________    _____

     3.1771      149.35     92.117       79    334    729    2.9793      650          255            395          2.6824           -1.5491          2  
     3.9655      180.34     122.08       19    229    729    3.8176      710          210            500          3.6809            -2.633          3  
     3.3081      156.67     103.54       99    334    729    3.0564      630          235            395          2.8323            -1.408          1  
     3.4482      139.52     85.993       39    229    759    3.2743      720          190            530          2.5075           -2.7583          1  
     3.8306      176.85      119.2       19    294    729    3.6499      710          275            435          3.5651           -2.2468          2  
     3.4701      145.87     111.34       99    319    699    3.2575      600          220            380          3.0761           -1.0609          1  
      3.733      196.27     145.09       39    294    789    3.5574      750          255            495          3.2482           -3.4094          3  
     3.0975      167.82     123.67     -236    114    454    2.8192      690          350            340          2.5781           -2.4782          2  
     3.2312      150.91     119.68      129    334    729    2.9267      600          205            395          1.8209           -1.4896          1  

[Devendra]

Thank you very much for helping me. One more little thing is how to resolve following error

X = T(:, new_T);

A table variable subscript must be a numeric array containing real positive integers, a logical array, a character vector, a string array, a cell array of character vectors, or a pattern scalar used to match variable names.

Dev

[Mathieu NOE]

this is not my code : X = T(:, new_T);

new_T is the table extracted from T , so T(:, new_T) is non sense (you cannot use a table as a table subscript

use the code I provided above (it works !!)