在Scilab中解决ODE [英] Solving ODE in Scilab

问题描述

我正在尝试通过解决ODE在Scilab中进行一些电路分析.但是我需要根据函数的当前值更改ODE.我已经使用RK4方法在Scala中实现了该解决方案，并且效果很好.现在，我尝试执行相同的操作，但是在Scilab中使用标准函数.而且它不起作用.我已经尝试过分别解决这两个ODE，这是可以的.

I am trying to do some electric circuit analysis in Scilab by solving an ODE. But I need to change an ODE depending on current value of the function. I have implemented the solution in Scala using RK4 method and it works perfectly. Now I am trying to do the same but using standard functions in Scilab. And it is not working. I have tried to solve these two ODEs seperately and it is OK.

clear
state = 0 // state 0 is charging, 1 is discharging
vb = 300.0; vt = 500.0; 
r = 100.0; rd = 10.0;
vcc = 600;
c = 48.0e-6;

function dudx = curfunc(t, uu)
    if uu < vb then state = 0
    elseif uu > vt state = 1
    end

    select state
    case 0 then // charging
        dudx = (vcc - uu) / (r * c)
    case 1 then // discharging
        dudx = - uu / (rd * c) + (vcc - uu) / (r * c)
    end
endfunction
y0 = 0
t0 = 0
t = 0:1e-6:10e-3

%ODEOPTIONS=[1, 0, 0, 1e-6, 1e-12, 2, 500, 12, 5, 0, -1, -1]
y = ode(y0, t0, t, 1e-3, 1e-6, curfunc)
clear %ODEOPTIONS
plot(t, y)

所以这里我要求解节点电压，如果节点电压超过最高阈值(vt)，则使用放电ODE；如果节点电压低于最低电压(vb)，则使用充电ODE .我试过玩%ODEOPTIONS但没有运气

so here I am solving for a node voltage, if node voltage is exceeding top threshold (vt) then discharging ODE is used, if node voltage is going below the bottom voltage (vb) then charging ODE is used. I have tried to play with %ODEOPTIONS but no luck

推荐答案

您还可以使用ode("root" ...)选项.

you can also use the ode("root"...) option.

代码将重组为 清除 状态= 0//状态0正在充电，1正在放电 vb = 300.0; vt = 500.0; r = 100.0； rd = 10.0; vcc = 600； c = 48.0e-6;

The code will ressemble to clear state = 0 // state 0 is charging, 1 is discharging vb = 300.0; vt = 500.0; r = 100.0; rd = 10.0; vcc = 600; c = 48.0e-6;

function dudx = charging(t, uu)
//uu<vt
  dudx = (vcc - uu) / (r * c)
endfunction
function e=chargingssurf(t,uu)
  e=uu-vt
endfunction

function dudx = discharging(t, uu)
//uu<vb
  dudx = - uu / (rd * c) + (vcc - uu) / (r * c)
endfunction
function e=dischargingssurf(t,uu)
  e=uu-vb
endfunction

y0 = 0
t0 = 0
t = 0:1e-6:10e-3

Y=[];
T=[];
[y,rt] = ode("root",y0, t0, t, 1e-3, 1e-6, charging,1,chargingssurf);
disp(rt)
k=find(t(1:$-1)<rt(1)&t(2:$)>=rt(1))
Y=[Y y];;
T=[T t(1:k) rt(1)];
[y,rt] = ode("root",y($), rd(1), t(k+1:$), 1e-3, 1e-6, discharging,1,dischargingssurf);
Y=[Y y];
T=[T t(k+1:$)];

plot(T, Y)

排放代码似乎有误...

The discharging code seems to be wrong...

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