How do I change one value in a matrix

I'm trying to create a game where the matrix is going to be n x n depending on what the user inputs. The game then starts by inputting values like 5 6 to represent row column. after that i what to change that one number to a random whole number between 1 and 3 to represent if the character has hit or miss! here is my code:

name = input('Your name:', 's');

fprintf('How big is your kingdom ' , name)
b =input('Enter an integer for the size of the board):');

board = zeros(b , b); 

side1 = 1;
side2 = 1;

board(side1,:) = (1:b);
board(:, side2) = (1:b);

fprintf('You have 12 knights left to defeat the 12 king');
board 

move = input('Enter your next move (row space column in brackets):');

board(move) = rand(3);

I think i'm getting the multiple inputs wrong as well.... i thought by having the user input both numbers at once with brackets would work but perhaps that is wrong as well.

Answer 1

[Star Strider]

I prefer inputdlg to input, so I used it here:

movec = inputdlg('Enter your next move (row space column in brackets):');
move = str2num(movec{:});
board(move(1),move(2)) = randi(3);

I also changed your rand call to randi. Your rand(3) command would create a (3x3) matrix of random numbers on the interval [0,1] which is not what your description says you want.

It seems to work.

[Sarah Huynh]

ohhhhh i didn't realize i put that thank you! Can you tell me what str2num is? is that saying string to number? i'm unsure and would like to understand!

[Star Strider]

I’ll be glad to explain it.

The inputdlg function returns a cell array of whatever inputs it receives. Since you’re only asking it for numbers here, it returns a cell string that includes the brackets and the numbers. The str2num function (along with the curly brackets {} reference to ‘movec’) then returns a (1x2) vector of double-precision numbers in the ‘move’ vector that are the coordinates you requested.

I would add a test to be sure the coordinates entered through the inputdlg call are within the address range of the matrix, and then continue looping until a correct set of coordinates are entered. (A while loop would probably be the best way of doing this.)

I would also use inputdlg for ‘name’. That code would become:

namec = inputdlg('Your name: ');
name = namec{:};