Plotting the function of single variable

13 次查看（过去 30 天）
Iftikhar Ahmed
Iftikhar Ahmed 2021-8-18
评论： Iftikhar Ahmed 2021-8-18
I am trying to plot the function N_21(p,s,t) given below.
The code is the following
%--------------------------------------------------------------------------------------------------------------------------------------------
syms h k x p q J
n0 = 400;
r0 = 1/n0;
gamma = 1.26;
r=@(p) r0 * gamma.^p;
N_21 =@(p,s,t) r0 .* n0 .* (2 .* s ./ (2.*s - 1)).^(p+1) .* symprod( r(J), J,[0, p-1]).*...
(exp(- r0 .* (2.*s-1) .* t)./(symprod( r(J) - r0, J,[1,p]))+...
symsum( exp(- r(q) .* (2.*s - 1) .* t)./((r0-r(q)).* (symprod(r(h) - r(q), h, 0, q-1) .* ...
symprod(r(h) - r(q), h, q+1, p))), q,[1, p]));
p2=plot(t, N_21(1,0.85,t),'b--', 'LineWidth',1.5 );
%--------------------------------------------------------------------------------------------------------------------------------------------
"p" and "s" are the parameters and can take positive values (p=1,2,3,4,.... and 0<=s<1). The reason for putting p and s in the code is to be free in choosing any desired value to them.
I can't figure out the error in the code why this is not running. Any suggestion/solution, please.
  2 个评论
John D'Errico
John D'Errico 2021-8-18
What error do you get in the code? When you just tell us you got an error, there are many things you may have done wrong. This forces us to run your code, when the error message itself would tell us much about what happened. So when you want to ask about an error, show the COMPLETE text of the error message. EVERYTHING IN RED.
Iftikhar Ahmed
Iftikhar Ahmed 2021-8-18
@John D'Errico
Below is the error I am getting:
"
Error using symengine
Inconsistent assumptions.
Error in sym/symsum (line 70)
rSym = mupadmex('symobj::map',fsym.s,'symobj::symsum',x.s,a.s,b.s);
Error in
Plots_slopes>@(p,s,t)r0.*n0.*(2.*s./(2.*s-1)).^(p+1).*symprod(r(q),q,0,p-1).*(exp(-r0.*(2.*s-1).*t)./(symprod(r(q+0.0000001)-r0,q,0,p))+symsum(exp(-r(q).*(2.*s-1).*t)./((r0-r(q+0.0000001)).*(symprod(r(h)-r(q),h,1,q-1).*symprod(r(h)-r(q),h,q+1,p))),q,0,p))
Error in Plots_slopes (line 62)
p2=plot(t,N_2(1,0.85,t),'r--', 'LineWidth',1.5 );"

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

David Hill
David Hill 2021-8-18
n0 = 400;
r0 = 1/n0;
gamma = 1.26;
p=20;%assumed
s=.7;%assumed
P=1:(p+1);
r=r0*gamma.^(0:p);
N=@(t)r0*n0*(2*s/(2*s-1))^(p+1)*prod(r(1:end-1))*(exp(-r0*(2*s-1)*t)/prod(r(2:end)-r(1))+sum(exp(-r(2:end)*(2*s-1)*t)./(r(1)-r(2:end)).*arrayfun(@(x)prod(r(P~=x)-r(x)),2:(p+1))));
t=0:.1:10;
n=zeros(size(t));
for k=1:length(t)
n(k)=N(t(k));
end
plot(t,n);

类别

在 Help Center 和 File Exchange 中查找有关 Mathematics 的更多信息

标签

产品


版本

R2018b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by