istable() returns false for my table

I create a table under certain conditions, later want to check if it is a table yet.

Checking in the command window I get this

K>> (app.Results2Table)

ans =

Columns 1 through 5

643705 644260 644760 645000 0

646934 647489 647989 648229 0

650201 0 0 0 0

K>> istable(app.Results2Table)

ans =

logical

0

Looks like a table to me

Answer 1

[Les Beckham]

That is definitely not a table. You can confirm that with the whos command. Tables are formatted differently when displayed. Specifically, they have variable names (that look like column titles).

[Les Beckham]

For example:

T = array2table(rand(5))

T = 5×5 table
     Var1        Var2        Var3        Var4         Var5  
    _______    _________    _______    _________    ________

    0.72169      0.44067    0.54442      0.51337     0.98782
    0.36857    0.0020561    0.42387      0.19171     0.71103
    0.60238      0.41035    0.83338    0.0030115     0.37504
    0.57584      0.21747    0.86724      0.93166     0.15564
    0.13459      0.56578    0.62416      0.53486    0.057996

[Gavin]

So it's not a table until I put the header on it even if I declare it as a table at the start. It's a matrix? I changed the check to ~isempty() and that works.

Thanks, that had me stumped.

[Steven Lord]

How exactly did you try to declare it as a table? What command did you use?

If you preallocated it to contain a certain amount of data like the following, that makes it an array (or since this is 2-dimensional, a matrix as per the definition used by the ismatrix function.) All table arrays are matrices, but it is not the case that all matrices or all arrays are tables.

a = zeros(5) % matrix and array, but not a table

a = 5×5

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

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Or if you did this, that makes it a cell array not a table.

b = {1, 2, 3, 4, 5}

b = 1×5 cell array
    {[1]}    {[2]}    {[3]}    {[4]}    {[5]}