Problem using quad2d with vector

Question

Scott Lines 2016-10-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/309202-problem-using-quad2d-with-vector

回答： Torsten 2016-10-26

Using below code with the variable t doesn't work, matrix dimensions don't agree, if the variable is replaced with a single number it does work (though that's not particularly useful), I've tried replacing it with a loop to no avail.

What am i missing?

lm = 1.75; 
Cm = 3.2E6;
fe = 1380;
H = 13.5;
% time and space
y = 0.0;
ro = 0.1;
x = ro;
ts = [0.1 97/24];           
Mt = 100; 
% t = logspace(log10(ts(1)*86400),log10(ts(2)*86400),Mt);   % [s]
t = linspace(ts(1)*86400, ts(2)*86400, Mt); % [s]
% calculated parameters
QL = fe/H;                   
z = H/2;
Dt = lm/Cm;             
r = sqrt(x.^2+y.^2);  
T = QL*(1/4/pi/lm)*...              
    (quad2d(@(f,ze) erfc(sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2)...
     /2/sqrt(Dt*t))/pi./sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2),0,pi,0,H)-...
     quad2d(@(f,ze) erfc(sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2)...
     /2/sqrt(Dt*t))/pi./sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2),0,pi,-H,0));

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Answer 1

KSSV 2016-10-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/309202-problem-using-quad2d-with-vector#answer_240749

You have to take care of element wise operations in that big expression T. As T is very big and clumsy, I have modified it to a loop, as below.

clc; clear all ;
lm = 1.75; 
Cm = 3.2E6;
fe = 1380;
H = 13.5;
% time and space
y = 0.0;
ro = 0.1;
x = ro;
ts = [0.1 97/24];           
Mt = 100; 
% t = logspace(log10(ts(1)*86400),log10(ts(2)*86400),Mt);   % [s]
tt = linspace(ts(1)*86400, ts(2)*86400, Mt); % [s]
% calculated parameters
QL = fe/H;                   
z = H/2;
Dt = lm/Cm;             
r = sqrt(x.^2+y.^2);  
T = zeros(size(tt)) ;
for i = 1:length(tt)
    t = tt(i) ;
T(i) = QL*(1/4/pi/lm)*...              
    (quad2d(@(f,ze) erfc(sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2)...
     /2/sqrt(Dt*t))/pi./sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2),0,pi,0,H)-...
     quad2d(@(f,ze) erfc(sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2)...
     /2/sqrt(Dt*t))/pi./sqrt(r^2+ro^2-2*r*ro*cos(f)+(z-ze).^2),0,pi,-H,0));
end