# MATLAB: If statements inside of while loop

if statementwhile loop

I would like to run this while loop for a inputted number of cycles. but if the input's at any point through out those cycles cause one of my equations to output to be <= 0 then I would like that equation to just output 0 for then on. I think that can be done with an if statement between each of my top 3 eaquations but I'm not sure how to do it. any help would be appreciated.
``% Predator-Prey Model Equationsclear,clc% variables, we have to set these at the begind0=input('Enter Starting population of Deer: ');m0=input('Enter Starting population of Moose: '); w0=input('Enter Starting population of Wolves: '); y=input('Enter Number of years to graph: ');i=1;k=1;%fixed ratesa=.0035; % Deer repop rateb = .0004; % Rate wolves find deerc=.0029; % Moose repop ratee=.00039; % rate wolves find moosef=.15; % wolves effiecency at making food into offspring (repop rate)g = .07;  % Death rate of wolves%h=.05; % an added death rate that could be used if you wanted to add in%deaths from people or other animals%equations% D=d0+d0^2*A-B*d0^2*w0-d0^2*H;% M=m0+m0^2*C-E*m0^2*w0-m0^2*H;% W=w0+w0^2*F-w0^2*G;%plot %% here is the general idea for the plot these equations don't have the%extra death rate like we talked about, those can be addedwhile k<=y    d(i)=d0+((d0^2)/2)*a-((d0^2)/2)*b*w0; % a=Deer repop rate  b=rate wolves find deer    m(i)=m0+((m0^2)/2)*c-((m0^2)/2)*e*w0;% c= Moose repop rate  e= rate wolves find moose    w(i)=w0+((w0^2)/2)*f*(m0*b+d0*e)-g*w0; %f= wolves effiecency at making food into offspring  g= death rate of wolves    d0=d(i);    m0=m(i);    w0=w(i);    i=i+1;    k=k+1;end%plottingplot(1:i-1, d, 'o');title('Deer Over Time')grid onaxis([0, i, 0, 100000])plot(1:i-1, m, 'o')grid onaxis([0, i, 0, 100000])title('Moose over time')plot(1:i-1, w, 'o')grid onaxis([0, i, 0, 25])title('wolves over time')%display final outputsdisp('Final amount of deer')disp(d0)disp('Final amount of Moose')disp(m0)disp('Final amount of Wolves')disp(w0)``

``flags = false(1,3);while k<=y    if flags(1)        d(i) = 0;    else        d(i)=d0+((d0^2)/2)*a-((d0^2)/2)*b*w0; % a=Deer repop rate  b=rate wolves find deer        if d(i) < 0            flags(1) = true;        end    end        if flags(2)        m(i) = 0;    else        m(i)=m0+((m0^2)/2)*c-((m0^2)/2)*e*w0;% c= Moose repop rate  e= rate wolves find moose        if m(i) < 0            flags(2) = true;        end    end        if flags(3)        w(i) = 0;    else        w(i)=w0+((w0^2)/2)*f*(m0*b+d0*e)-g*w0; %f= wolves effiecency at making food into offspring  g= death rate of wolves        if w(i) < 0            flags(3) = true;        end    end        d0=d(i);    m0=m(i);    w0=w(i);    i=i+1;    k=k+1;end``