Plotting problem and while loops

I am having an issue with plotting my code using a while loop. I want it to show a negative downward line with the y-axis ranging from 0 to 50 and the x-axis ranging from 1 to whatever the maximum number of days it is. When I plot it, the y-axis goes from 1 to -1 in increments of -0.2, and the x-axis goes from 6 to 8 in increments of 0.5. The line doesn't even show up when I zoom out. I am unsure of what I am doing wrong. Any idea on how to fix this?

clear;clc
MandM = 50;
day = 1;
while MandM > 0
    day = day + 1
    MandM = MandM - randi(3)
    MandM = MandM - 7
end
MandM = 0
plot(day,MandM)
xlabel('day')
ylabel('M&Ms remaining')

[James Tursa]

Please delete the image and post your code as text highlighted with the CODE button instead. We can't copy & run images at our end.

[David Fletcher]

You need to save each value of MandM in the loop - and having gone to the effort of doing that, preferably not overwrite it with 0 when the loop ends

Answer 1

[DGM]

Something like this:

% initial conditions
MandM = 50;
day = 1;

while MandM > 0
    % operate on the last element of the vector and append the result
    day = [day day(end) + 1];
    MandM = [MandM (MandM(end) - randi(3) - 7)];
end

plot(day,MandM)
xlabel('day')
ylabel('M&Ms remaining')