How to display hidden element in matrix when we add the coordinate?

I have

x = 

1 0 0
0 1 0
0 0 1

      y=
  . . .
  . . .
  . . .

I used y to hide elements from x as in y=x but they look like dots as I wanted to hide the elements

I want to reveal hidden elements by entering coordinates

Example

If I enter (2,2)

I want y to be displayed as

      y =
  . . .
  . 1 .
  . . .

Also,

If I were to reveal neighboring elements if x = 1, how would I do that

[Geoff Hayes]

Sahil - please clarify what you mean by you hid with y and provide more details on how this relates to the coordinate (2,2). (What problem are you trying to solve?)

[Sahil Bajaj]

When I say I hid with y

I replaced elements of x with a '.' and named that matrix y

(2,2) is a coordinate ( as in row no,column no)

[Walter Roberson]

Are you trying to program the game "minesweeper" ?

[Sahil Bajaj]

kinda

Answer 1

[Guillaume]

It would help if you used valid matlab syntax in your question, so we don't have to guess whether your input is a cell array, a character array or something else. It would also help if you'd said what coordinate system you use ([row, column], [x, y]?).

Possibly, this is what you want:

%input variables:
x = [1 0 0; 0 1 0; 0 0 1];
y = repmat('.', [3 3]); %assume y is a char array. Maybe it's a cell array?
coords = [2 2]; %assume that first value is row, 2nd value is column?

%replace dot at coord by 1
y(coords(1), coords(2)) = '1';

%reveal neighbours where x == 1
%step 1 find bounding box. Be careful of edge, hence min/max below:
top = max(1, coords(1)-1);  
bottom = min(size(y, 1), coords(1)+1);
left = max(1, coords(2)-1);
right = min(size(y, 2), coords(2)+1);
%step 2 extract bounding box from x and y
suby = y(top:bottom, left:right);
subx = x(top:bottom, left:right);
%step 3 replace neighbour that are 1 in x by '1' in y
suby(logical(subx)) = '1';
%step 4 put bounding box back in y
y(top:bottom, left:right) = suby;

However, it sounds to me that you're lacking basic knowledge of indexing in matlab, so before you try to write an interactive game, I would advise to first learn the basics of matlab.