Why does table creation produce error "VariableNames property must contain one name for each variable in the table"?

Can you please revise the following line of code to eliminate the error "VariableNames property must contain one name for each variable in the table"? I am stumped.

    T = table(rand(30,8), 'VariableNames', ...
      {'var1' 'var2' 'var3' 'var4' 'var5' 'var6' 'var7' 'var8'});

Answer 1

[KAE]

Just figured this out: have to use array2table,

   T = array2table(rand(30,8), ...
      'VariableNames', {'var1' 'var2' 'var3' 'var4' 'var5' ...
      'var6' 'var7' 'var8'});

However if you want to assign other properties besides names, you have to do that separately, unlike the table command,

T.Properties.VariableUnits = {'kg' 'm' 'W' 's' 'g' 'kg' 'm' 'W'};

[Brent F]

Nice find! Another MATLAB oddity to add to the list of annoyances/inconsistencies.

[Emily Jung]

This is so helpful! Thanks for sharing the tip :)

[Steven Lord]

Another MATLAB oddity to add to the list of annoyances/inconsistencies.

It's not an inconsistency.

When you call table like that, you're asking MATLAB to create a table with one variable, not eight. That one variable happens to contain eight columns. As a smaller example, here's a table with one variable that contains a two-column matrix. Note that the size of T1 is [5 1] not [5 2].

X = randi(10, 5, 2);
T1 = table(X, VariableNames = "Coordinates")

T1 = 5×1 table
    Coordinates
    ___________

      2    5   
      9    8   
      9    2   
      7    7   
      3    8   

size(T1)

ans = 1×2

5 1

When you use array2table instead, MATLAB creates one variable per column of the input. The size of T2 is [5 2].

T2 = array2table(X, VariableNames = ["X coordinate", "Y coordinate"])

T2 = 5×2 table
    X coordinate    Y coordinate
    ____________    ____________

         2               5      
         9               8      
         9               2      
         7               7      
         3               8      

size(T2)

ans = 1×2

5 2

Answer 2

[Ivy Fatima]

Error using array2table

The RowNames property must contain one name for each row in the table.