# How could I solve this error?

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Bajdar Nouredine on 20 Aug 2021
Answered: darova on 23 Aug 2021
this code does not have any problem with respect to r and t, but when I add interval for t and r it gives this error
thanks for helping
B=(2/pi)^(1/2);
r1=0.00001;
k=0.42;
Cp=3600;
g=1000;
rho=1048;
Tb=37;
qm=300;
w=0.0005;
ra=0.01;
%%
c=w*rho*Cp;
r_distance=ra*2;
time_total=1;
dr=r_distance/10;
dt=0.1;
rmesh=0:dr:r_distance;
tmesh=0:dt:time_total;
rskip=2;
tskip=2;
number_iterations=2;
nr=length(rmesh);
nt=length(tmesh);
V=zeros(nt,nr);
for i=1:nt
for j=1:nt
for m=1:number_iterations
q = int((((B*(rp*sqrt(c))^(-0.5)*sin(rp*sqrt(c))/(sqrt(rp)*B*(sqrt(c))^(-0.5)*sin(sqrt(c)))))-1)*rp*sin(m*pi*rp),rp,0,1); % the integral r prime from 0 to 1
first_term = symsum((exp((m*pi)^2+c)*(-tmesh(j)))*sin(m*pi*rmesh(i))*q, m, 1, 10); % a summation
end
end
end
Error using sym/symsum (line 52)
Cannot compute the sum with respect to '1'. The summation index must be a symbolic variable.
Error in test (line 36)
first_term = symsum((exp((m*pi)^2+c)*(-tmesh(j)))*sin(m*pi*rmesh(i))*q, m, 1, 10); % a summation
Bajdar Nouredine on 20 Aug 2021
@darova it solved, thanks,
darova on 21 Aug 2021

darova on 23 Aug 2021
You are using the same variable as in for loop. That why you have an error