Date: Jan 26, 2013 6:53 AM
Author: maia
Subject: use quadl and give me this error=??? Undefined function or method 'isfinite

i m new to matlab and i want plot these equation

unfortunately when i write following code it give me error

??? Undefined function or method 'isfinite' for input arguments of type 'sym'.

Error in ==> quadl at 74
if ~isfinite(y(1))

Error in ==> test10 at 84
ss=quadl(f , 1 , 2);
i need to run this code successfully in 1 day please if you know anything that can help me let me know

here is my code and thank you in advance

close all
clear
clc
re=0.5;
t=0:1:10;
syms k r n z
s=k*r;
m=k*re;
eps=70/9600;


%*************************************
%for n=0
%*************************************
pin0= besseli(1,k*r);
pin01=besselk(1,k);
pin04=pin0*pin01;
pin02=((1-eps)*besseli(0,k)*besselk(0,k)*diff(besselk(0,k)));
pin03=1/(eps*diff(besselk(0,k))*besseli(0,k)-besselk(0,k)*diff(besseli(0,k)));
pin07=pin03*pin02;
pin08=pin04*pin07;
%ezplot(pin08);
%*************************************
%for n=1
%*************************************
pin1= besseli(1,k*r);
pin11=besselk(1,k);
pin14=pin1*pin11;
pin12=((1-eps)*besseli(1,k)*besselk(1,k)*diff(besselk(1,k)));
pin13=1/(eps*diff(besselk(1,k))*besseli(1,k)-besselk(1,k)*diff(besseli(1,k)));
pin17=pin13*pin12;
pin18=2*pin14*pin17;
pin19=cos(t);
pin10=pin18*pin19;
%ezplot(pin10);

%*************************************
%for n=2
%*************************************

pin2= besseli(2,k*r);
pin21=besselk(2,k);
pin24=pin2*pin21;
pin22=((1-eps)*besseli(2,k)*besselk(2,k)*diff(besselk(2,k)));
pin23=1/(eps*diff(besselk(2,k))*besseli(2,k)-besselk(2,k)*diff(besseli(2,k)));
pin27=pin23*pin22;
pin28=2*pin24*pin27;
% pin9=cos(t);
% pin10=pin8*pin9;
%ezplot(pin27);

%*************************************
%for n=3
%*************************************
pin3= besseli(3,k*r);
pin31=besselk(3,k);
pin34=pin3*pin31;
pin32=((1-eps)*besseli(3,k)*besselk(3,k)*diff(besselk(3,k)));
pin33=1/(eps*diff(besselk(3,k))*besseli(3,k)-besselk(3,k)*diff(besseli(3,k)));
pin37=pin33*pin32;
pin38=2*pin34*pin37;
% pin9=cos(t);
% pin10=pin8*pin9;
%ezplot(pin37);
%*************************************
%for n=4
%*************************************

pin4= besseli(4,k*r);
pin41=besselk(4,k);
pin44=pin4*pin41;
pin42=((1-eps)*besseli(4,m)*besselk(4,k)*diff(besselk(4,k)));
pin43=1/(eps*diff(besselk(4,k))*besseli(4,k)-besselk(4,k)*diff(besseli(4,k)));
pin47=pin43*pin42;
pin48=2*pin44*pin47;
%pin9=cos(t);
%pin10=pin8*pin9;
%ezplot(pin47);


sigma=pin48*cos(4*t)+pin38*cos(3*t)+pin28*cos(2*t)+pin18*cos(t)+pin08;

f = @(k , r )sigma;
ss=quadl(f , 1 , 2);


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