Counting 4 Couple Table Arrangements in MATLAB

[bor0000]

I tried to write a function that would count all possible combinations that 4 couples could sit at a table assuming no man can sit next to his wife or next to another man. and 1wife and 1 husband sit at fixed positions. my problem doesn't compile and it says i either have too many or too few "end" statements. So please find the mistake:
%4wifes problem: man and wife sit at the corners of the table. others may sit so that no man sits next to his wife or another man
%how many possible arrangements?
function c = fourcouples(trials)
pos=[1,0,0,0,0,0,0,0,0,1];
x=[];
c=0;
count=1;
counter=0;
while count[ trials %set matrix x with all possible combinations

for i=2:9
pos(i)=rand;
if pos(i)[ =.25
pos(i)=1;
else if pos(i)[ =.50
pos(i)=2;
else if pos(i)[ =.75
pos(i)=3;
else
pos(i)=4;
end %of if
end %set random variables, end of forloop1

k=0;
for j=2:8
if pos(j)~=pos(j+1)
k=k+1;
end %end of if
end %end for loop2

if k==7
x=[x;pos]; %augment x by a new arrangement
counter=counter+1; %number of rows of rows of x
end %of if
count=count+1;
end %of while loop
i=1;
y=[];
while i[ =counter %get rid of dupblicate arrangements by setting new matrix y
z=y;
y=[y;x(i,:)];
if det(y)==0
y=z;
else
c=c+1;
end
i=i+1;
end
end
return

 

[bor0000]

up. also i wrote a program for "count the probability that n tosses will give k heads" , based on doing many random trials. that program did compile. but i found it to be rather slow. i.e. the most it would do was 100k trials.

after the current problem compiles, i'll try to do monte carlo simulations.

 

[LeBrad]

If you're using Matlab, you want to replace 'else if' with 'elseif'. As it is, Matlab wants to put an if inside your else, which would explain the lack of end statements. And what is ' [ ' ?

 

[bor0000]

wow thanks! i'll see if it now compiles based on this "elseif"! "[" was really "<", i just copied it to this forum incorrectly.