matlab三重积分图,三重积分在积分时一直在运行，无法画图

syms r1 r2 r3 x

Path_loss_exponent=3;    %los and nlos

Antenna_Gain=10^1.8;

power=1;   %w

%power=1000;   %mw

R=100;   %m

rd=200;   %m

Noise_power=10;

T=-20:3:20;

TT=10.^(0.1*T);

%............................................

r3=sqrt(r1^2+r2^2+2*r1*r2*cos(x));

P1=0.975;   %no connect to A-BS

%......................................................

mean3=1;

mean4=1;

fangcha3=10^0.45;    %los 4.5db

fangcha4=10^0.72;    %nlos 7.2db

shang1=(exp(2*mean3+fangcha3^2))*(exp(fangcha3^2)-1)+(exp(2*mean4+fangcha4^2))*(exp(fangcha4^2)-1);

xia1=(exp(mean3+(fangcha3^2)/2)+exp(mean4+(fangcha4^2)/2))^2;

fangcha_of_ub=sqrt(log(shang1/xia1+1));

mean_of_ub=log(exp(mean3+fangcha3^2/2)+exp(mean4+fangcha4^2/2))-fangcha_of_ub^2/2;

ab2=log(TT*Noise_power*(r1^Path_loss_exponent)/(power*Antenna_Gain));

ac2=(ab2-mean_of_ub)/fangcha_of_ub;

outage_ub=erfc(-ac2/sqrt(2))/2;    % outage of ub

%..............................................

mean5=1;

mean6=1;

fangcha5=10^0.48;    %los 4.8db

fangcha6=10^0.69;    %nlos 6.9db

shang2=(exp(2*mean5+fangcha5^2))*(exp(fangcha5^2)-1)+(exp(2*mean6+fangcha6^2))*(exp(fangcha6^2)-1);

xia2=(exp(mean5+(fangcha5^2)/2)+exp(mean6+(fangcha6^2)/2))^2;

fangcha_of_ba=sqrt(log(shang2/xia2+1));

mean_of_ba=log(exp(mean5+fangcha5^2/2)+exp(mean6+fangcha6^2/2))-fangcha_of_ba^2/2;

ab3=log(TT*Noise_power*(r3^Path_loss_exponent)/(power*Antenna_Gain));

ac3=(ab3-mean_of_ba)/fangcha_of_ba;

outage_ba=erfc(-ac3/sqrt(2))/2;

%...................................................

PP1=int(int(int((1-P1*outage_ub.*outage_ba)*2*r1*r2/(pi*rd^2*R^2),x,0,2*pi),r1,0,rd),r2,0,R);

figure;

plot(T,PP1,'--gd');

xlabel('SNR Threshold(dB)');

ylabel('Coverage Probablity');