How to overcome this error?

Error using vertcat

Dimensions of arrays being concatenated are not consistent.

Error in smoothmod (line 55)

RHOar = [RHOar.'; 0];

Answer 1

[Matt J]

RHOar is not a row vector, as you seem to expect it to be at line 55.

[madhan ravi]

 RHOar = [RHOar.'; zeros(size(RHOar.'))];

Answer 2

[Sudhakar Shinde]

%Example:
a=[1 2 3 4]
B= [a;0]
%This throws an eroor as you mentioned 

%Correct concatenation
B=[a,0]
%or
B=[a';0]

[Sudhakar Shinde]

if this throws error :

RHOar = [RHOar'; 0];

you could try:

RHOar = [RHOar; 0];