%% Problem 6.3.
%% Calls P6_3 which calls P6_3 fun
%% Carol Lucas

mess='Progam pauses after every figure. Hit return to continue.'

Mess='Part B - isolated cell, accomplished by setting alpha (or gc)= 0'
figure(1);clf;
w=.2;

%%  The system is particularly sensitive around an initial condition of -30.
%%  Above this, the cell oscillates.  The nullclines can be examined as in Chapter 2
%%  Below shows that oscillations start if i>0 or so.
Mess='i=-5'
[t,x]=ode45('P6_3fun',[0 200],[-30;w;-30;w],[],0,-5,-5,0);plot(t,x(:,3));pause;
Mess='i=0'
[t,x]=ode45('P6_3fun',[0 200],[-30;w;-30;0],[],0,-5,0,0);plot(t,x(:,3));pause;


Mess='Part C - Different conductances, cells originally in different states'

gc=.01
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,1);
beat=fanal(t,x(:,1));plot(t,x(:,1),t,x(:,3),t,beat);pause;
gc=.15
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,1);
beat=fanal(t,x(:,1));plot(t,x(:,1),t,x(:,3),t,beat);pause;gc=.5
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,1);
beat=fanal(t,x(:,1));plot(t,x(:,1),t,x(:,3),t,beat);pause;
gc=1
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,1);plot(t,x(:,1),t,x(:,3));pause;

Mess='Part D - Different Areas, cells originally in different states'
Mess='Note that larger alphas do decrease the rate of the first cell'

gc=.3;
alpha=1
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,alpha);
beat=fanal(t,x(:,1));plot(t,x(:,1),t,x(:,3),t,beat);pause;
alpha=.8
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,alpha);
beat=fanal(t,x(:,1));plot(t,x(:,1),t,x(:,3),t,beat);pause;
alpha=.5
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,alpha);
beat=fanal(t,x(:,1));plot(t,x(:,1),t,x(:,3),t,beat);pause;
alpha=.1
[t,x]=ode45('P6_3fun',[0 400],[-30;w;-40;w],[],gc,5,-1,alpha);
beat=fanal(t,x(:,1));plot(t,x(:,1),t,x(:,3),t,beat);pause;