How can I define string scalars for a name(for example, one for my name and one for today's date) in command windows?

Sorry I'm new to matlab.

Is this what I'm supposed to do?

a=['Tim'];

b=['09/13'];

When I tried creating a column vector consisting of a and b, it said the matrices size don't match or something like that. Using the scalars defined above, how can you build and define a column vector of the info?

Answer 1

[Star Strider]

Use a cell array:

ab = {'Tim' datestr(now,'mm/dd')}

produces:

ab = 

      'Tim'    '09/13'

The command:

ab{:}

produces:

ans =

Tim

ans =

09/13

and:

celldisp(ab)

produces:

ab{1} =

Tim

ab{2} =

09/13

and:

sprintf('%s\n\n', ab{:})

produces:

ans =

Tim

09/13

There may be other possibilities as well, but I can’t think of them just now.

[Image Analyst]

You created a row vector. To create a column vector of cells:

ab = {'Tim'; datestr(now,'mm/dd')} % Use semicolon

[Star Strider]

Correct, I forgot the semicolon. Other results don’t change.

The other output function I forgot is:

fprintf('%s\n\n', ab{:})

that produces simply:

Tim

09/13

[Tim]

it worked, but I guess I will just use help command to get to know those scripts. Thank you so much.

[Star Strider]

My pleasure!

Cell arrays are powerful tools to store and manipulate data. In most situations, it’s necessary to convert them back to numeric arrays to do any calculations on them, though. I’ve been working with MATLAB for a while, and I’m still discovering new ways to use them.

Another one I just remembered is a way to easily recover the individual elements of the ‘ab’ cell array:

[a b] = ab{:}

produces:

a =

Tim

b =

09/13

that sort of brings us back to where we started.

[Image Analyst]

Like using deal() without actually using deal().

[Star Strider]

Very much so!

When I refreshed my memory of deal, its documentation mentioned:

-------------------------------------------------------------------------------------------------------------------------------------------------

Note Beginning with MATLAB® Version 7.0 software, you can access the contents of cell arrays and structure fields without using the deal function. See Example 3, below. -------------------------------------------------------------------------------------------------------------------------------------------------

The ‘guts’ of Example 3 (without the explanation) being:

[a,b,c,d] = C{:}
[name1,name2] = A(:).name

This comes in handy when you pass an argument list to a function without passing the individual arguments as a list in the function itself:

qc = {3 5 7};
qf = @(a,b,c) a.*b.^c;
qfc = qf(qc{:})

elutes:

qfc =

     234.3750e+003

Makes it possible to so a lot of wonderful magic with a minimum of typing.

We can thank Tim for getting us off on this cell-array tangent! I actually learned some stuff while writing it.

Answer 2

[Image Analyst]

That will work, though they're called "string literals" http://en.wikipedia.org/wiki/String_literal not "string scalars" and you don't need the square brackets. If you want a column vector, you can either create a cell array with a in the first cell and b in the second cell:

a= 'Tim';
b = '09/13';
ca = cell(2, 1); % Initialize a 2 row column vector.
ca{1} = a;
ca{2} = b;
celldisp(ca);

or you can convert a and b to column arrays and concatenate

c = [a(:);b(:)]

[Image Analyst]

See the FAQ for a good intuitive description of cell arrays:

http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F

[Tim]

Thanks for enlightening me! When I did c = [a(:);b(:)], it produced something like this

T

i

m

0

9

/

1

3