MATLAB: Table dispaly with char array

table dispaly

Got the below code, not sure why the table display of the char array is not right

Tval = table(name, x_t, tvals, 'VariableNames',{'Fund','Allocation','Dollar_Value'})
Tval = 
    Fund    Allocation    Dollar_Value
    ____    __________    ____________
    BHP      0.22894      [1x11 char] 
    NAB      0.19151      [1x11 char] 
    CSR      0.38988      [1x11 char] 
    AGL      0.13727      [1x11 char] 
    NCP     0.052397      [1x11 char] 
Tval.Dollar_Value
ans = $22894412.3
$19150910.7
$38988264.5
$13726664.3
$5239748.2

How to get the strings to display? Thanks!

Best Answer

You're using a char array, almost certainly not what you want for a variety of reasons. Mostly, char matrices require awkward padding with spaces and don't have many of the text processing functions that cell arrays of char vectors have. (I won't even get into why you're using text for a numeric quantity, presumably you have good reasons.) If you use a cell array of char vectors, table will display the full text:

>> table([1;2;3],{'abcdefgh';'abcdefghabcdefgh';'abcdefghabcdefghabcdefgh'})
ans =
    Var1               Var2           
    ____    __________________________
    1       'abcdefgh'                
    2       'abcdefghabcdefgh'        
    3       'abcdefghabcdefghabcdefgh'

In the most recent version of MATLAB, R2016b, you're probably even better off using the new string type. Hope this helps.

Related Solutions

MATLAB: Existing table, populate a column with string (receiving errors)

You are close, but you are trying to assign a character vector to a double variable (NaN = not a number). You can see that if you run the command summary(mytable).

You also do not need to put the text into a cell if you use the string data type.

See if you can get this code to work for your needs.

myArray = nan(5,2)
mytable = array2table(myArray);
mytable.Properties.VariableNames = {'colA', 'colB'};
mytable2 = convertvars(mytable,"colB",'string');
mytable2.colA(:) = 459;
mytable2.colB(:) = "words"

You say you have a lot of data. If the variables already exist, you could do something like this:

colA = nan(5,1);
colB = strings(5,1);
mytable = table(colA,colB);
mytable.colA(:) = 459; % just a random number, proof-of-concept that it works
mytable.colB(:) = "words" % this throws errors

MATLAB: Are strings stored in an extra cell within a table

The reason why xTable{1,1} is a scalar cell array is due to the way the data is stored internally in the table. The whole column is stored internally as a cell array and since individual cells of a cell array can contain anything, including several strings, they must be returned as cell arrays.

Similar to your example, consider

x = {'FirstString'; {'SecondString', ''}; ''};
xtable = cell2table(x);
xtable{2, 1}  %has to be returned as cell array since it contains two strings.

Note that with your example, there is a very simple way to test if a cell is empty, using ismissing:

x = {'FirstString'; 'SecondString'; ''};
xtable = cell2table(x);
ismissing(xtable)

Also, since R2016b, there's now a much better way to store strings, using the new string class. matlab will do what you expected if you use that to store your strings.

 x = {'FirstString'; 'SecondString'; ''};
 xstring = string(x);
 xtable = array2table(xstring)
 class(xtable{1, 1})  %return string not cell
 xtable{3,1} == ''    %test for empty string. DO NOT USE isempty

Not that if you use string see test for empty strings

Best Answer

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MATLAB: Existing table, populate a column with string (receiving errors)

MATLAB: Are strings stored in an extra cell within a table

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