table less than operator

hi,

I'm having this error : Undefined operator '<' for input arguments of type 'table'.

how can I write the operator less than for table?

I ttied using gt(A,B) and lt(A,B) but it still give me this error.

I still want to use table and not to convert the table to array.

thanks!

[Walter Roberson]

What does it mean to you for a table to be less than something? Are you sure you do not instead want to compare the content of a variable in the table to something?

[sani]

Hi,

yes this what I'm trying to do

Answer 1

[Matt J]

Are you sure you do not instead want to compare the content of a variable in the table to something?... yes this what I'm trying to do.

Then why are you trying to apply < or > to the entire table? You should be applying it to a specific variable, like in the following example:

T =

  5×6 table

    LastName     Age    Smoker    Height    Weight    BloodPressure
    _________    ___    ______    ______    ______    _____________

    'Sanchez'    38     true        71       176       124     93  
    'Johnson'    43     false       69       163       109     77  
    'Li'         38     true        64       131       125     83  
    'Diaz'       40     false       67       133       117     75  
    'Brown'      49     true        64       119       122     80  

>> T.Age<=40

ans =

  5×1 logical array

   1
   0
   1
   1
   0

[sani]

maybe this will help to understand what I'm tring to do:

this is my code, and I want to compare between the cell in the i location to the cell (i-1) location for the entire table, and if the cell (i-1) equal less than the cell value i than the cell in the location i will be equal to the sum of the values of cells i and i-1

prev = 0;       
sum = 0;
for i = 2:height(T1(:,1))
    if lt(prev,T1.time(i))
        sum = sum + prev;
    end
    prev = T1(i,1);
    T1.time(i) = T1.time(i)+sum;
end

[Walter Roberson]

prev = 0; 

That is a specific numeric value.

    if lt(prev,T1.time(i))

First round, you compare the specific numeric value to the numeric time. All is well.

         prev = T1(i,1);

You just set prev to the entire table row - a table with an unknown number of variables and one row in it. Wouldn't it make more sense to set prev to T1.time(i) ?

[sani]

yes so I guess I didn't understand table syntex well, thanks!

[Walter Roberson]

Correction, T1(i,1) is not an entire row, but it is a sub-table with one row and the same variable as the first variable in the table T1.

[sani]

So in my case time variable in in the 1st column of the table, is it becaus this syntex call a sub-table and not for a variable it didn't worked?

[Walter Roberson]

Change

prev = T1(i,1);

to

prev = T1{i,1};

[sani]

Thanks!