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Error while using NDSolve?

Romero Padilla Romero

Romero Padilla Romero, Tec de monterrey

Posted 3 years ago

This code doesn't work, Please, I need help. $Version Clear[nN, beta0, gamma, sigma, iI0, sol, sS, eE, iI, rR] nN = 100 000; (* Estudio para 100 mil personas ) beta0 = 1.0; gamma = 1 / 5; ( la enfermedad dura, de media, cinco días ) sigma = 1 / 7; ( el periodo asintomático dura, de media, siete días ) iI0 = 1; ( un infectado al principio ) ( tiempo t en días ) sol = NDSolve[\:f01csS'[t] == (-beta0) (sS'[t]) * (iI[t]) \:f00c nN, eE'[t] == (beta0)(sS[t]) (iI[t]) \:f00c (nN) - (sigma) * (eE[t]), iI'[t] == (sigma)(eE[t]) - (gamma) (iI[t]), rR'[t] == (gamma)(iI[t]), sS[0] == (nN) - (iI0), (eE[0]) == (iI0), (iI[0]) == 0, (rR[0]) == 0\:f027, {sS, eE, iI, rR}, {t, 0, 240}]; Plot[Evaluate[{sS[t], eE[t], iI[t], rR[t]} /. sol], {t, 0, 120}, PlotRange \[RightArrow] All, AxesOrigin \[RightArrow] {0, 0}, AxesLabel \[RightArrow] {"días",}, PlotLegends \[RightArrow] {"susceptibles", "expuestos", "infectados", "recuperados"}] Attachments:* nofuncuiona.nb

This code doesn't work, Please, I need help.

$Version
Clear[nN, beta0, gamma, sigma, iI0, sol, sS, eE, iI, rR]
nN = 100 000; (* Estudio para 100 mil personas *)
beta0 = 1.0;
gamma = 1 / 5; (* la enfermedad dura, de media, cinco días *)
sigma = 1 / 7; (* el periodo asintomático dura, de media, siete días *)
iI0 = 1; (* un infectado al principio *)
(* tiempo t en días *)
sol = NDSolve[\:f01csS'[t] == (-beta0) * (sS'[t]) * (iI[t]) \:f00c nN,
eE'[t] == (beta0)*(sS[t]) * (iI[t]) \:f00c (nN) - (sigma) * (eE[t]),
iI'[t] == (sigma)*(eE[t]) - (gamma) * (iI[t]),
rR'[t] == (gamma)*(iI[t]),
sS[0] == (nN) - (iI0), (eE[0]) == (iI0), (iI[0]) == 0, (rR[0]) == 0\:f027,
{sS, eE, iI, rR}, {t, 0, 240}];
Plot[Evaluate[{sS[t], eE[t], iI[t], rR[t]} /. sol], {t, 0, 120},
PlotRange \[RightArrow] All, AxesOrigin \[RightArrow] {0, 0}, AxesLabel \[RightArrow] {"días",},
PlotLegends \[RightArrow] {"susceptibles", "expuestos", "infectados", "recuperados"}]

POSTED BY: Romero Padilla Romero

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Bill Nelson

Posted 3 years ago

Restart Mathematica and, before doing anything else, scrape this code off the screen and paste it into your notebook and run it and report what you get nN=100000;beta0=1.0;gamma=1/5;sigma=1/7;iI0=1; sol=NDSolve[{sS'[t]==-beta0sS'[t]iI[t]/nN, eE'[t]==beta0sS[t]iI[t]/nN-sigmaeE[t], iI'[t]==sigmaeE[t]-gammaiI[t],rR'[t]==gammaiI[t], sS[0]==nN-iI0,eE[0]==iI0,iI[0]==0,rR[0]==0}, {sS[t],eE[t],iI[t],rR[t]},{t,0,240}]; Plot[Evaluate[{sS[t],eE[t],iI[t],rR[t]}/.sol],{t,0,120}, PlotRange->All,AxesOrigin->{0,0}] If it works then compare that character by character with the code you showed above and look at every tiny difference.

Restart Mathematica and, before doing anything else, scrape this code off the screen and paste it into your notebook and run it and report what you get

nN=100000;beta0=1.0;gamma=1/5;sigma=1/7;iI0=1;
sol=NDSolve[{sS'[t]==-beta0*sS'[t]*iI[t]/nN,
eE'[t]==beta0*sS[t]*iI[t]/nN-sigma*eE[t],
iI'[t]==sigma*eE[t]-gamma*iI[t],rR'[t]==gamma*iI[t],
sS[0]==nN-iI0,eE[0]==iI0,iI[0]==0,rR[0]==0},
{sS[t],eE[t],iI[t],rR[t]},{t,0,240}];
Plot[Evaluate[{sS[t],eE[t],iI[t],rR[t]}/.sol],{t,0,120},
PlotRange->All,AxesOrigin->{0,0}]

If it works then compare that character by character with the code you showed above and look at every tiny difference.

POSTED BY: Bill Nelson