Convert a numerical variable in a table to string

I have a table T with 5 variables/columns

The 3rd variable (pic), with 75 rows, is basically pic = [70, 40, 60, 70, 50, 65...] How can I convert this one variable in the able to a string? I need to do that so I can carry out strrep later on.

T = string (T(:,3)) is not working. Any ideas where I am going wrong?

Thanks heaps!

[Guillaume]

Wrong indexing! {} is used to extract data from a table, not (). Or as per Barak answer, use the .nameofvariable indexing.

However, I need to do that so I can carry out strrep later on. Converting from number to string and back is slow. What is it you want to replace? It can probably be done with going through strings.

[Boushra Dalile]

I am trying to piece together a series of replacements if a separate condition is satisfied, specifically:

If Table x (table with variables, and variable 3 (pic) contains numbers such as 10, 30, 40, 60, 30, 70) contains 35, then - replace all '60' with 'z1' - replace all '40' with 'z2' - replace all '30' with 'z3'

If not, - replace all '60' with 'y1' - replace all '40' with 'y2' and so forth.

[Guillaume]

It seems odd to want to replace numerical value with text. Nonetheless, all this replacement can be done a lot more easily and certainly a lot faster without having to convert any of the numbers to text beforehand.

To show you how to do that, you need to be a bit clearer on what is replaced by what. Give an example using valid matlab syntax.

edit: see Walter's answer for what I mean, using a lookup table will be a lot faster than converting numbers to strings

Answer 1

[Walter Roberson]

zlookup = {'z1', 'z2', 'z3'};
T3 = T{:,3};
[tf, idx] = ismember(T3, [60, 40, 30]);
out = cell(length(tf),1);
out(tf) = zlookup(idx(tf));
out(~tf) = sprintfc('%g', T3(~tf));
T{:,3} = out;

Answer 2

[Stephen23]

As the MATLAB documentation explains, you need to use curly braces to access the contents of a table:

string(T{:,3})

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-table.html

Answer 3

[CARLOS RIASCOS]

Starting from the fact that you have the variable 'pic = [70, 40, 60, 70, 50, 65 ...]' defined you could convert that row vector like this:

 g = num2str(pic)

The variable g will contain the string produced by pic.

[Walter Roberson]

Be sure to pass in a column vector.

The result will be a char array. To convert to string objects, cellstr() and string() the results.