How do I increase the x-axis to make my action potentials bigger

I_add = 0.1;

tspan = 1000;

v = -65;

m = 0;

n = 0.1;

h = 1;

s0 = [v; m; n; h];

[t1,s1] = ode15s(@hodgkinhuxeqoriginal,[0 tspan], s0, [], I_add);

figure(1)

subplot(2, 2, 1)

plot(t1,s1(:,1));

xlabel('Time');

ylabel('Membrane Potential');

title('Voltage time series');

subplot(2, 2, 2)

plot(t1,s1(:,2));

xlabel('Voltage');

ylabel('m');

title('t vs. m');

subplot(2, 2, 3)

plot(t1,s1(:,3));

xlabel('Voltage');

ylabel('n');

title('t vs. n');

subplot(2, 2, 4)

plot(t1,s1(:,4));

xlabel('Voltage');

ylabel('h');

title('t vs. h');

function dSdt = hodgkinhuxeq(t,s0,I_add)

%Function hodgkinhuxeq

% Inputs: t - time

% I_add - input current

% v - voltage

%potentials

g_k = 36;

g_na = 120;

g_l = 0.3;

E_k = -77;

E_na = 50;

E_l = -54;

Cm = 1;

%variables

v = s0(1);

m = s0(2);

n = s0(3);

h = s0(4);

%eqs

a_m = -0.1*((v+35)/(exp(-0.1*(v+35))-1));

b_m = 4.0*exp((-v-60)/18);

a_h = 0.07*exp(-0.05*(v+60));

b_h = 1/1+exp(-0.1*(v+30));

a_n = -0.01*(v+50)/(exp(-0.1*(v+50))-1);

b_n = 0.125*exp(-0.0125*(v+60));

%dv/dt sections

K_1 = ((g_k*(n^4))*(v-E_k));

Na_1 = (g_na*(m^3)*h)*(v-E_na);

L_1 = g_l*(v-E_l);

%derivat

dVdt = (-1/Cm)*((K_1)+(Na_1)+(L_1)-I_add);

dmdt = a_m*(1-m)-b_m*m;

dhdt = a_h*(1-h)-b_h*h;

dndt = a_n*(1-n)-b_n*n;

dSdt = [dVdt; dmdt; dndt; dhdt];

end

Answer 1

[Star Strider]

The X-limits need to be reduced in order to show the detail, and the last subplot needs to have its axes rescaled to show the detail.

I_add = 0.1;

tspan = 1000;
v = -65;
m = 0;
n = 0.1;
h = 1;
s0 = [v; m; n; h];
% [t1,s1] = ode15s(@hodgkinhuxeqoriginal,[0 tspan], s0, [], I_add);
[t1,s1] = ode15s(@hodgkinhuxeq,[0 tspan], s0, [], I_add);

figure(1)
subplot(2, 2, 1)
plot(t1,s1(:,1));
xlabel('Time');
ylabel('Membrane Potential');
title('Voltage time series');
xlim([0  50])


subplot(2, 2, 2)
plot(t1,s1(:,2));
xlabel('Voltage');
ylabel('m');
title('t vs. m');  
xlim([0  50])

subplot(2, 2, 3)
plot(t1,s1(:,3));
xlabel('Voltage');
ylabel('n');
title('t vs. n');
xlim([0  50])

subplot(2, 2, 4)
plot(t1,s1(:,4));
xlabel('Voltage');
ylabel('h');
title('t vs. h');
xlim([0  50])
set(gca, 'XScale','log', 'YScale','log')

function dSdt = hodgkinhuxeq(t,s0,I_add)
%Function hodgkinhuxeq
%   Inputs: t - time
%           I_add - input current
%           v - voltage 


%potentials 
g_k = 36;
g_na = 120;
g_l = 0.3;
E_k = -77;
E_na = 50;
E_l = -54;
Cm = 1;

%variables


v = s0(1);
m = s0(2);
n = s0(3);
h = s0(4);

%eqs

a_m = -0.1*((v+35)/(exp(-0.1*(v+35))-1));
b_m = 4.0*exp((-v-60)/18);
a_h = 0.07*exp(-0.05*(v+60));
b_h = 1/1+exp(-0.1*(v+30));
a_n = -0.01*(v+50)/(exp(-0.1*(v+50))-1);
b_n = 0.125*exp(-0.0125*(v+60));

%dv/dt sections
K_1 = ((g_k*(n^4))*(v-E_k));
Na_1 = (g_na*(m^3)*h)*(v-E_na);
L_1 = g_l*(v-E_l);

%derivat
dVdt = (-1/Cm)*((K_1)+(Na_1)+(L_1)-I_add);
dmdt = a_m*(1-m)-b_m*m;
dhdt = a_h*(1-h)-b_h*h;
dndt = a_n*(1-n)-b_n*n;

dSdt = [dVdt; dmdt; dndt; dhdt];
end

.

[Nyimatoulie Cham]

Thank youuuu!!!!!

[Star Strider]

My pleasure!

.

[Nyimatoulie Cham]

How can I get m n h on the same graph? I tried "hold on" and removed the subplot but the graph does not look right, it is supposed to be a graph of gNA and gK showing m n h

subplot(2, 2, 2)

plot(t1,s1(:,2));

xlabel('Voltage');

ylabel('m');

title('t vs. m');

xlim([0 50])

subplot(2, 2, 3)

plot(t1,s1(:,3));

xlabel('Voltage');

ylabel('n');

title('t vs. n');

xlim([0 50])

subplot(2, 2, 4)

plot(t1,s1(:,4));

xlabel('Voltage');

ylabel('h');

title('t vs. h');

xlim([0 50])

set(gca, 'XScale','log', 'YScale','log')

[Star Strider]

Use the hold function or yyaxis depending on the desired result (the log scales are necessary in order to correctly show ‘h’) —

I_add = 0.1;

tspan = 1000;
v = -65;
m = 0;
n = 0.1;
h = 1;
s0 = [v; m; n; h];
% [t1,s1] = ode15s(@hodgkinhuxeqoriginal,[0 tspan], s0, [], I_add);
[t1,s1] = ode15s(@hodgkinhuxeq,[0 tspan], s0, [], I_add);

figure(1)
subplot(2, 2, 1)
plot(t1,s1(:,1));
xlabel('Time');
ylabel('Membrane Potential');
title('Voltage time series');
xlim([0  50])


subplot(2, 2, 2)
plot(t1,s1(:,2));
xlabel('Voltage');
ylabel('m');
title('t vs. m');  
xlim([0  50])

subplot(2, 2, 3)
plot(t1,s1(:,3));
xlabel('Voltage');
ylabel('n');
title('t vs. n');
xlim([0  50])

subplot(2, 2, 4)
plot(t1,s1(:,4));
xlabel('Voltage');
ylabel('h');
title('t vs. h');
xlim([0  50])
set(gca, 'XScale','log', 'YScale','log')

figure
plot(t1,s1(:,4));                                       % Plot 'h'
hold on
plot(t1,s1(:,2));                                       % Plot 'm'
hold off
xlabel('Voltage');
% ylabel('h');
% title('t vs. h');
xlim([0  50])
set(gca, 'XScale','log', 'YScale','log')
legend('h','m', 'Location','best')                      % Add 'legend' Object
title('Using ‘hold’')

figure
yyaxis left
plot(t1,s1(:,4));                                       % Plot 'h'
ylabel('h')
set(gca, 'YScale','log')
yyaxis right
plot(t1,s1(:,2));                                       % Plot 'm'
xlabel('Voltage');
ylabel('m');
% title('t vs. h');
xlim([0  50])
set(gca, 'XScale','log')
title('Using ‘yyaxis’')

function dSdt = hodgkinhuxeq(t,s0,I_add)
%Function hodgkinhuxeq
%   Inputs: t - time
%           I_add - input current
%           v - voltage 


%potentials 
g_k = 36;
g_na = 120;
g_l = 0.3;
E_k = -77;
E_na = 50;
E_l = -54;
Cm = 1;

%variables


v = s0(1);
m = s0(2);
n = s0(3);
h = s0(4);

%eqs

a_m = -0.1*((v+35)/(exp(-0.1*(v+35))-1));
b_m = 4.0*exp((-v-60)/18);
a_h = 0.07*exp(-0.05*(v+60));
b_h = 1/1+exp(-0.1*(v+30));
a_n = -0.01*(v+50)/(exp(-0.1*(v+50))-1);
b_n = 0.125*exp(-0.0125*(v+60));

%dv/dt sections
K_1 = ((g_k*(n^4))*(v-E_k));
Na_1 = (g_na*(m^3)*h)*(v-E_na);
L_1 = g_l*(v-E_l);

%derivat
dVdt = (-1/Cm)*((K_1)+(Na_1)+(L_1)-I_add);
dmdt = a_m*(1-m)-b_m*m;
dhdt = a_h*(1-h)-b_h*h;
dndt = a_n*(1-n)-b_n*n;

dSdt = [dVdt; dmdt; dndt; dhdt];
end

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