I would like find a matrix from a row and column vectors

Hello, I have a column vector xxb of 201 elements and a row vector rr of 501 elements and I would calculate c =xxb^2+rr^2-R^2 with R=0.05. I have to obtain a matrix of (501x201)size.But i found (501x501). Here is below my code. Anyone has a idea. Thank you in advance, Adam

 xb=-5:0.05:5;

 xxb=xb';% column vector
 r=0:0.01:5;
 rr=r;% Row vector
 R= 0.05;
 for l=1:length(xxb);
   for m=1:length(rr);
      a(l)=2.*xxb(l);
      c(l,m)=xxb(l).^2+rr(m).^2+R^2;
    end 
 end

Answer 1

[Honglei Chen]

If you want 501x201, then you may want to make rr a column and xxb a row

rr = rr(:);
xxb = xxb(:).';
c = bsxfun(@plus,rr.^2,xxb.^2)+R^2;

or with your current configuration

c = (bxsfun(@plus,xxb.^2,rr.^2)+R^2).';

Answer 2

[adam]

Hello Honglei,

Thank you for your answer. I managed finally to obtain my matrix using for loop. The aim of this code is to find the area of the intersection of two cercles that must to be matrix in order to use it in another code.But I can't find the good result. Here below my code. May be have you an idea. thank you very much in advance.

if true

xb=-5:0.05:5;

 xxb=xb';
dr=0.01;
r=0:dr:5;
rr=r;% colonne ligne
ABDN1=ABDN;% colonne ligne
w2=2.25;
R= 0.05;
for l=1:length(xxb);
    for m=1:length(rr);

% paramètres a,c,xp,yp
a(l)=2.*xxb(l);
c(l,m)=xxb(l).^2+rr(m).^2-R^2;
if (a(l)>0) &(a(l)<0)
  xp(l,m)=c(l,m)./a(l);
  yp(l,m)=R^2-((((2.*c(l,m))-(a(l).^2))./(2.*a(l))).^2);
else 
  xp(l,m)=0;
  yp(l,m)=0;
end

% angle theta

    theta(l,m)=atan((sqrt(yp(l,m)))./xp(l,m));

if R<rr(m) inter(l,m)=0;

elseif xxb(l)==0 inter(l,m)=2*pi;

elseif xxb(l)<abs(R-r(m)) inter(l,m)=2.*pi; elseif xxb(l)>r(m)+R inter(l,m)=0;

 else
 inter(l,m)=(atan((sqrt(yp(l,m)))./xp(l,m)));

% part1(l,m)= (r(m).^2).*acos((xxb(l).^2 + r(m).^2 - R^2)/(2.*xxb(l).*r(m))); % part2(l,m) = (R^2).*acos((xxb(l).^2+ R ^2- r(m).^2)/(2.*xxb(l).*R)); % part3(l,m) = 0.5.*sqrt((-xxb(l)+r(m)+R)*(xxb(l)+r(m)-R)*(xxb(l)-r(m)+R)*(xxb(l)+r(m)+R)); % % inter(l,m) = part1(l,m) + part2 (l,m)- part3(l,m);

end

end

end

end