Error using vertcat Dimensions of arrays being concatenated are not consistent.

Asked by Martina Della Monica

Martina Della Monica (view profile)

on 10 Sep 2019
Latest activity Answered by darova

darova (view profile)

on 11 Sep 2019
Dear all,
I implement this function:
function [SP_Simulation]=get_survivalprobability(a,b,w,dt,m,k)
for i=1:k
for j=1:m
hzrd(i,j)=exp(a(i)+b*w(i,j)) ;
end
end
h1=hzrd(1,:) ;
SP1=(sum(exp(h1*-dt)))/m ;
for i=1:k-1
h=(hzrd(i,:)+hzrd(i+1,:)).*-dt;
SP_others(i)=sum(exp(h),2)./m ;
SP_Simulation=[SP1 ; SP_others];
end
end
when I try to use it for the following main code:
k=5;
m=3000;
b=0.01 ;
SP=repmat(0.98,k,1) ;
w=rand(k,m);
fun=@(a) (get_survivalprobability(a,b,w,dt,m,k)-SP);
% find f(a)=0 such that equation (4.6) holds, given
% an initial guess a0
a0=ones(1,k);
[a] = fsolve(fun,a0);
% find hazard rates with the new parameters a
for i=1:k
for j=1:m
h(i,j)=exp(a(i)+b*w(i,j))
end
end
it shows me the following error: Error using vertcat Error using vertcat Dimensions of arrays being concatenated are not consistent.
Thank you in advance
Regards,
Martina

darova (view profile)

on 11 Sep 2019

MATLAB doesn't know if SP_others is column or row vector. By default - row
SP_others(i)=sum(exp(h),2)./m ;
Then you are trying to concantenate
SP_Simulation=[SP1 ; SP_others];
Also i recommend you to pre-allocate memory for matrices hzrd = zeros(k,m);
SP_others = zeros(k-1,1); % COLUMN