Cm=0.945;?%0.945
gL=0.3;%0.3
gNa=120;%120
gKdr=36;%36

?
?
?
EL=16;%EL=-54EK=-77ENa=50
ENa=115;
EK=-12;


t（1）=0;
d=0.01;
?
?
?
V（1）=-64;
h（1）=0;
n（1）=0;
m（1）=0;
I=6.4;
?
?
for?i=1:1:100000
????U=V（i）;
????H=h（i）;
????N=n（i）;
????M=m（i）;
????
??

????am=0.1*（25-U）/（exp（0.1*（25-U））-1）;
????bm=4.0*exp（-U/18）;
????ah=0.07*exp（-U/20）;
????bh=1/（1+exp（0.1*（30-U）））;
????z=exp（0.1*（10-U））-1;
????an=0.01*（10-U）/z;
????bn=0.125*exp（-U/80）;
????m_inf=am/（am+bm）;
????h_inf=ah/（ah+bh）;
????n_inf=an/（an+bn）;
????tau_n=1/（an+bn）;
????tau_h=1/（ah+bh）;
????tau_m=1/（am+bm）;
?
?
????INa=gNa*M^3*H*（ENa-U）;??
????IKdr=gKdr*N^4*（EK-U）;
????IL=gL*（EL-U）;
????Iion=INa+IKdr+IL+I;
??
?????
????k11=Iion/Cm;
????k21=（h_inf-H）/tau_h;
????k31=（n_inf-N）/tau_n;
????k41=（m_inf-M）/tau_m;
?
???
?????
?????U=V（i）+0.5*d*k11;
?????H=h（i）+0.5*d*k21;
?????N=n（i）+0.5*d*k31;
?????M=m（i）+0.5*d*k41;
????
??????
?
?
????am=0.1*（25-U）/（exp（0.1*（25-U））-1）;
????bm=4.0*exp（-U/18）;
????ah=0.07*exp（-U/20）;
????bh=1/（1+exp（0.1*（30-U）））;
????z=exp（0.1*（10-U））-1;
????an=0.01*（10-U）/z;
????bn=0.125*exp（-U/80）;
????m_inf=am/（am+bm）;
????h_inf=ah/（ah+bh）;
????n_inf=an/（an+bn）;
????tau_n=1/（an+bn）;
????tau_h=1/（ah+bh）;
????tau_m=1/（am+bm）;
?
?
????
?
????INa=gNa*M^3*H*（ENa-U）;??
????IKdr=gKdr*N^4*（EK-U）;
????IL=gL*（EL-U）;
????Iion=INa+IKdr+IL+I;
?????
????k12=Iion/Cm;
????k22=（h_inf-H）/tau_h;
????k32=（n_inf-N）/tau_n;
????k42=（m_inf-M）/tau_m;