Removing quotations from table display

Trying to display a symbolic matrix in a table, however directly displaying using table or array2table causes the symbolic matrix to be displayed as:

After casting the symbolic matrix as a string, double quotes surround each input:

clear all;
clc;


numVars = input('How many joints would you like to enter: ');
DH = sym(zeros(numVars,4));
DHparameters = ["a"; "alpha"; "d"; "theta"];
i = string(1:numVars);

for j=1:numVars
    clc;
    disp("JOINT "+num2str(j)+" of "+num2str(numVars));
    pR = input('Is this joint prismatic or revolute (p/r): ','s');
    DH(j,1) = sym(input("Enter DH parameter a for joint " + num2str(j)+": "));
    DH(j,2) = sym(input('Enter DH parameter alpha: '));
    
    if pR=='p'
       DH(j,4) = sym(input('Enter DH parameter theta: '));
       DH(j,3) = sym("d_"+num2str(j),'real');
    else
        DH(j,3) = sym(input('Enter DH parameter d: '));
        DH(j,4) = sym("theta_"+num2str(j),'real');
    end
    
end

clc;
table1 = array2table(DH, 'RowNames',i,'VariableNames',{'a', 'alpha', 'd', 'theta'});
%table1 = table(i,string(DH),'VariableNames',{'i', 'a alpha d theta'});
disp(table1);

If there is a different way to display this to the user I am open to that as well!

[dpb]

The double quotes are a fignewton of the MATLAB display logic to indicate the type of the variable -- strings are double-quoted, cell-strings are single-quoted so you can visibly tell them apart. The quotes of either style are NOT part of the data and cannot be removed in the default output in the command window.

They don't hurt anything, do they, why not just leave as is?

If you export the table to some other format, only the data will be retained unless you choose something like quoted strings in a CSV file (always a good choice if using CSV, of course).

[Connor LeClaire]

No it doesn't hurt anything, it just makes the table (in my opinion) look cluttered and less-clear. I'd like to have the data displayed without them, just the data with no curly brackets, no quotes etc.

[dpb]

As Scott shows below, it can be done, but turns into a fair amount of work pretty quickly.

Answer 1

[Scott MacKenzie]

Seems like you just want a more visually appealing presentation for the user. Something like this might work:

vNames = {'a' 'alpha' 'd', 'theta'};
T = array2table(["0" "0" "1/2" "theta_1"; "0" "0" "d_2" "pi/2"], 'VariableNames', vNames);

C = [num2cell(1:height(T))' table2cell(T)]';
s = newline;
s = [s sprintf('==================================\n')];
s = [s sprintf('row %4s%8s%8s%10s\n', vNames{:})];
s = [s sprintf('----------------------------------\n')];
s = [s sprintf('%3d %4s%8s%8s%10s\n', C{:})];
s = [s sprintf('==================================\n')];
disp(s);

==================================
row    a   alpha       d     theta
----------------------------------
  1    0       0     1/2   theta_1
  2    0       0     d_2      pi/2
==================================

[Connor LeClaire]

That looks great! Is it possible to include the row numbering in this display? Is it also possible to center the column labels to the data of that column (the longest data for ex. theta_1 in the last column).

[Scott MacKenzie]

Glad you like it. I just added some code to include the row numbers. Centering isn't really possible, since we are dealing with a monospaced font and you can't control character positions with the pixel-level granularity needed. As @dpb notes, creating and formatting ASCII tables is a lot of work and a tad finicky. Good luck.

[dpb]

Anything is possible, just how much effort are you willing to expend counting columns, writing format strings, etc., etc., etc., ...

The MATLAB command window is NOT designed as nor intended to be a document presentation window; TMW has (or at least has had) some document prep tools/toolboxen; I don't know what the status is for them now; you might want to look into that on the product site.

Alternatively, perhaps your purposes would be better served by writing the table to a spreadsheet and formatting it there for the user. Once you write it at the command window, it's going to be gone/overwritten at the next input command, anyways...

[Connor LeClaire]

Ah ok, good to know. It's more a sanity check for the user to make sure their values are correct for what they expect.

Thanks for all your help!

Answer 2

[dpb]

It's more a sanity check for the user to make sure their values are correct for what they expect.

And there's where the purpose of and value of the "" come in to play -- you are able to see if, for example, there are superfluous blanks in the data field this way that would be completely hidden otherwise, but perhaps cause a failure of a text search in string-matching code.

While I agree it is sometimes a little off-putting, the basics of the command window are well served by the choices TMW has made.

Two things I have done on occasion when I did want to make the presentation "cleaner" --

1. Use cellstr() instead of string() -- the single quotes aren't quite as heavy and if there's nothing being done that is really dependent upon the string class in the application, but just looking as here, unlikely to lose anyfunctionality.
2. Convert to categorical -- that way, since it is a not a type of string variable, MATLAB doesn't add any quotes:

vNames = {'a' 'alpha' 'd', 'theta'};
T=array2table(["0" "0" "1/2" "theta_1"; "0" "0" "d_2" "pi/2"], 'VariableNames', vNames);
T.a=categorical(T.a);
T.alpha=categorical(T.alpha);
T.d=categorical(T.d);
T.theta=categorical(T.theta);

Then you can write

>> disp(T)

    a    alpha     d      theta 
    _    _____    ___    _______
    0      0      1/2    theta_1
    0      0      d_2    pi/2   
>> 

Of course, you can wrap the conversion of the symbolic to string inside the call to categorical when creating the table; I don't have the TB so started with Connor's string version...