how toggle this warning using unstack function

T1 = table(year(prof_monthly.Data),month(prof_monthly.Data),prof_monthly.Profit); 

Result = unstack(T1, 'Var3', 'Var2');

Warning: Table variable names that were not valid MATLAB identifiers have been modified. Since

table variable names must be unique, any table variable names that happened to match the new

identifiers also have been modified.

To use the original INDVAR values as table variable names, set 'VariableNamingRule' to 'preserve'.

[Star Strider]

Related — how to create table Date/Value

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Answer 1

[Voss]

load('matlab_T1.mat')
T1

T1 = 25×3 table
    Var1    Var2     Var3 
    ____    ____    ______

    2022      1     276.85
    2022      2     2380.8
    2022      3      14223
    2022      4     988.75
    2022      5     7353.6
    2022      6     -257.6
    2022      7      10241
    2022      8     1775.1
    2022      9     525.35
    2022     10     2624.5
    2022     11      499.8
    2022     12       5.45
    2023      1     4917.8
    2023      2     298.63
    2023      3     6495.9
    2023      4      -4932

Option 1: Toggling the warning:

warning("off","MATLAB:table:ModifiedVarnamesUnstack")
Result = unstack(T1, 'Var3', 'Var2')

Result = 3×13 table
    Var1      x1        x2        x3        x4        x5        x6        x7        x8         x9        x10       x11       x12  
    ____    ______    ______    ______    ______    ______    _______    _____    _______    _______    ______    ______    ______

    2022    276.85    2380.8     14223    988.75    7353.6     -257.6    10241     1775.1     525.35    2624.5     499.8      5.45
    2023    4917.8    298.63    6495.9     -4932    2840.6    -1818.4    270.3    -931.75    -4233.9    1960.1    4084.2    3541.8
    2024    568.48       NaN       NaN       NaN       NaN        NaN      NaN        NaN        NaN       NaN       NaN       NaN

warning("on","MATLAB:table:ModifiedVarnamesUnstack")

Option 2: Using 'VariableNamingRule', 'preserve':

Result = unstack(T1, 'Var3', 'Var2', 'VariableNamingRule', 'preserve')

Result = 3×13 table
    Var1      1         2         3         4         5          6         7         8          9         10        11        12  
    ____    ______    ______    ______    ______    ______    _______    _____    _______    _______    ______    ______    ______

    2022    276.85    2380.8     14223    988.75    7353.6     -257.6    10241     1775.1     525.35    2624.5     499.8      5.45
    2023    4917.8    298.63    6495.9     -4932    2840.6    -1818.4    270.3    -931.75    -4233.9    1960.1    4084.2    3541.8
    2024    568.48       NaN       NaN       NaN       NaN        NaN      NaN        NaN        NaN       NaN       NaN       NaN

Pick the option (if any) that gives the variable names you want in Result.

Answer 2

[Hassaan]

The warning message you're seeing in MATLAB when using the unstack function on your table T1 is related to the naming of table variables. In MATLAB, table variable names must be valid MATLAB identifiers. This means they must begin with a letter and can be followed by letters, digits, or underscores. They also need to be unique within a table.

In your case, when you unstack T1, MATLAB is trying to create new variable names based on the values in the 'Var2' column of your table. If these values are not valid MATLAB identifiers, or if they create duplicates, MATLAB automatically modifies them to create valid and unique variable names. This is what triggers the warning.

To address this, you have two options:

Option 1: Modify Variable Names to be Valid MATLAB Identifiers

Ensure that the values in Var2 column (which you're using as new variable names) are valid MATLAB identifiers. You can do this by preprocessing these values before using unstack. For example:

% Convert Var2 values to strings and replace invalid characters
T1.Var2 = strrep(string(T1.Var2), ' ', '_');
T1.Var2 = matlab.lang.makeValidName(T1.Var2);

% Now use unstack
Result = unstack(T1, 'Var3', 'Var2');

Option 2: Use 'VariableNamingRule' to 'preserve'

Set the 'VariableNamingRule' property of the table to 'preserve'. This will keep the original values as variable names, even if they are not valid MATLAB identifiers. However, be aware that this might make it harder to reference these variables in your code later.

% Set VariableNamingRule to 'preserve' and Now use unstack
Result = unstack(T1, 'Var3', 'Var2', 'VariableNamingRule', 'preserve')

Note that using 'preserve' can lead to variable names that are not standard MATLAB identifiers, which might complicate subsequent operations on the table.

Choose the approach that best fits your needs. If you need to programmatically access the table variables later, it's usually better to ensure they are valid MATLAB identifiers. If the exact names are important for the interpretation of your data and you don't need to access them programmatically, then preserving the original names could be more suitable.

------------------------------------------------------------------------------------------------------------------------------------------------

If you find the solution helpful and it resolves your issue, it would be greatly appreciated if you could accept the answer. Also, leaving an upvote and a comment are also wonderful ways to provide feedback.

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[Luca Re]

Error using .

Unknown table property: VariableNamingRule.

Error in Predator_TableProfitMonth_Struct (line 21)

T1.Properties.VariableNamingRule = 'preserve';

[Hassaan]

@Luca Re Try now.

------------------------------------------------------------------------------------------------------------------------------------------------

If you find the solution helpful and it resolves your issue, it would be greatly appreciated if you could accept the answer. Also, leaving an upvote and a comment are also wonderful ways to provide feedback.

Professional Interests

• Technical Services and Consulting
• Embedded Systems | Firmware Developement | Simulations
• Electrical and Electronics Engineering

Feel free to contact me.

Answer 3

[the cyclist]

warning("off","MATLAB:table:ModifiedAndSavedVarnames")
warning("on", "MATLAB:table:ModifiedAndSavedVarnames")

[Luca Re]

it did not work

warning( "off" , "MATLAB:table:ModifiedAndSavedVarnames" );
T1 = table(year(prof_monthly.Data),month(prof_monthly.Data),prof_monthly.Profit); 

Result = unstack(T1, 'Var3', 'Var2');

Warning: Table variable names that were not valid MATLAB identifiers have been modified. Since

table variable names must be unique, any table variable names that happened to match the new

identifiers also have been modified.

To use the original INDVAR values as table variable names, set 'VariableNamingRule' to 'preserve'.

[the cyclist]

Sorry, I did not read your question carefully enough. I get a similar error when I load variables from file, and I thought that was the issue.