我正在尝试用ode45模拟神经元的Morris-Lecar模型。
我在初始化ode45调用时遇到了麻烦,文档无法帮助我。我知道我必须通过一个函数调用ode45,然后从我的主脚本中调用该函数。
一般而言,我对ODE的掌握有限,似乎难以理解初始化ODE45调用所需的语法。
另外,我被指示使用一个时间范围作为变量“pulse”,但是该函数没有时间范围的输入(似乎是一个变量,不是固定的),该函数从主脚本接收输入并发送具有ode45功能的其他功能。馈入ode45的函数也有一个时间输入,但是我仍然无法弄清楚如何输入时间范围。指令非常清楚,主脚本中使用的函数在任何时间都不会接受变量。
如果您能指出我在初始化过程中犯的任何明显错误,将不胜感激。
当前(以下)版本的错误代码如下:
Error using ODEequation (line 89)
Not enough input arguments.
Error in odearguments (line 88)
f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.
Error in ode45 (line 114)
[neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, odeArgs, odeFcn, ...
Error in ODEquestion (line 32)
[t Vm]=ode45(@ODEequation,[-20 20],[-30, 0.1]',[],constants, stim_on, stim_off, amp);
Error in YoonS_Lab3_EBME308_Fall2012 (line 355)
[t Vm] = ODEquestion(20,100,30)
我认为这可以归结为我不存在但仍需要时间的输入。
问题涉及
Cm * dVm / dt = -Gm(Vm-Vrest) - Gca Minf (Vm - Eca) - Gk w(Vm - Ek) + pulse(t)
dw/dt = (wInf - w) / Tau-w;
wInf = (1+tanh(Vm/30)) / 2;
mInf = (1+tanh(Vm+1)) / 2;
Tau-w = 5/ (cosh(Vm/60));
Cm = membrane leakage capacticance;
Gm = membrane leakage conductance;
Vm = membrane voltage;
Vrest = membrane voltage @ neuron resting
Gca = max Ca conductance through membrane
Gk = max K conductance through membrane;
mInf refers = P ( Ca ion channel open )
wInf refers = P ( K ion channel open )
Tau-w = rate which K channels respond to change in membrane voltage
Eca = reversal potential of Ca
Ek = reversal potential of K
pulse(t) = stimulus applied to neuron
pulse(t) = A (stim-on <= t <= stim-off) or 0 (else);
作为变量。
我创建了一个发送到ode45的函数,如下所示。
function dy = ODEequation(t, Vm, w, constants, stim_on, stim_off, amp)
wInf = (1 + tan(Vm / 30)) / 2
mInf = (1 + tan((Vm + 1)/ 15)) / 2
tauW = 5/ (cosh(Vm/60))
pulse = amp * ((stim_on < t ) - ( t >= stim_off));
dy(1) = y(1) * ((-constants(2) - constants(4) * constants(9) - constants(5) * y(2)) + (constants(2) * constants(3) + constants(6) * constants(4) * constants(9) + constants(5) * y(2) * constants(7) + constants(11))) / constants(1) ;
dy(2) = = ( constants(8) - y(2) )/constants(10)
dy = dy'
和传递的功能如下
function [t Vm] = ODEquestion(stim_on, stim_off, amp)
%i)
Cm = 1;
Gm = 0.5;
Vrest = -50;
Gca = 1.1;
Gk = 2;
Eca = 100;
Ek = -70;
%ii)
Vm(1) = -30;
w(1) = 0.1;
%iii)
wInf = (1 + tan(Vm / 30)) / 2
mInf = (1 + tan((Vm + 1)/ 15)) / 2
tauW = 5/ (cosh(Vm/60))
IC1 = Vm(1) % = -30
IC2 = w(1) % = 0.1
pulse = amp %* ((stim_on < t ) - ( t >= stim_off));
constants = [Cm , Gm, Vrest, Gca, Gk, Eca, Ek, wInf, mInf, tauW, pulse];
[t Vm]=ode45(@ODEequation,[-20 20],[-30, 0.1]',[],constants, stim_on, stim_off, amp);
最佳答案
从help ode45
:
因此,函数ODEFUN
仅需要两个输入(t
和y
),而您的函数需要7个输入。
您可以按照this site或this question上的说明解决此问题:
wrapper = @(t,Vm) ODEequation(t, Vm, w, constants, stim_on, stim_off, amp);
[t Vm]=ode45(wrapper, [-20 20],[-30, 0.1]',[],constants, stim_on, stim_off, amp);
例如,通过创建一个小型包装函数,该函数在转发
ode45
插入的变量时传递所有常量。