Index exceeds the number of array elements (1).

SumA(1) = 0;
SumB(1) = 0;
for i = 2:10000
PlayerA = randi([1,2]);
PlayerB = randi([1,2]);
if (PlayerA + PlayerB) == 2
    SumB = (SumB(i-1) + 1);    %Line 21
 elseif (PlayerA + PlayerB) == 3
     SumA = (SumA(i-1) + 1);    %Line 23
 elseif (PlayerA + PlayerB) == 4
     SumB = (SumB(i-1) + 1);    %line 25
end
 
end

This is supposed to be a game of Odds vs Evens that is played 10,000 times.

The error messages change between lines 21, 23, 25. All have the same message. 'Index exceeds the number of array elements (1).'

I want the score (Variable 'Sum') to be a vector so I can plot any range from the vector (Points [1:50] or [1000: 1500] for example)

I don't understand what is causing the error to appear; is it a syntax error?

Answer 1

[Emmanuel Lela]

SumA(1) = 0;
SumB(1) = 0;
for i = 2:10000
PlayerA = randi([1,2]);
PlayerB = randi([1,2]);
if (PlayerA + PlayerB) == 2
    SumB(i) = (SumB(i-1) + 1);        %
    SumA(i) = SumA(i-1);              %
 elseif (PlayerA + PlayerB) == 3
     SumA(i) = (SumA(i-1) + 1);       %
     SumB(i) = SumB(i-1);             %
 elseif (PlayerA + PlayerB) == 4
     SumB(i) = (SumB(i-1) + 1);       %
     SumA(i) = SumA(i-1);             %
end
 
end

Figured it out....