Thread Subject: length of array

have an array:

P{a,b}

how do i find the length of P{2,b} i.e. where a is fixed and for all values of b

have tried:
sum(cellfun(@length,P)) but this does not allow for {a,b} individually

thanks
P

P Sherry:
<SNIP cell acrobatics...

> P{a,b}
> how do i find the length of P{2,b}...

one of the solutions

     c={
          1:2 1:3
          1:4 1:5
          1:6 1:7
     };
     n=cellfun(@length,c(:,2))

us

"P Sherry" <pistolpetesherry@nospam.hotmail.com> wrote in message <f8l6hk$epd$1@fred.mathworks.com>...
> have an array:
>
> P{a,b}
>
> how do i find the length of P{2,b} i.e. where a is fixed and for all values of b
>
> have tried:
> sum(cellfun(@length,P)) but this does not allow for {a,b} individually
>
> thanks
> P


Try x=numel(P{2,b}).

> n=cellfun(@length,c(:,2))
> Try x=numel(P{2,b}).

both work but think n=cellfun(@length,c(:,2)) works best for what im doing

NEW PROBLEM:

i have a loop for l and want to use it to find a value not already used in the array P{a}.

i had the following which partly works... som of the time but not all of the time???

for l = 1:N
    if ~any(P{2} == l-1)

is there another form of this? there is also an inner loop i.e. P{2,b} so l-1 cannot = any of {2,:}

ps thanks for the prior replies.

any help with the ^^^^^^ would be much appreciated

P

In article <f8lldc$h41$1@fred.mathworks.com>,
P Sherry <pistolpetesherry@nospam.hotmail.com> wrote:

>NEW PROBLEM:

>i have a loop for l and want to use it to find a value not already used in the array P{a}.

>i had the following which partly works... som of the time but not all of the time???

>for l = 1:N
> if ~any(P{2} == l-1)

>is there another form of this?


find( ~ismember( 0:N-1, P{2} ), 1 )

> there is also an inner loop i.e. P{2,b} so l-1 cannot = any of {2,:}

What is the size of P? Is it a 1 x something cell array, each
member of which is an array? Or is it a 2 x something cell array,
each member of which is an array? When you write P{2,b} do
you mean "the b'th column of the 2nd row of P", or do you mean
"the b'th element of the array P{2}" ? If P is really a 2 x something
cell array, P{2} is the same as P{2,1} .
--
Programming is what happens while you're busy making other plans.

> find( ~ismember( 0:N-1, P{2} ), 1 )
>
> > there is also an inner loop i.e. P{2,b} so l-1 cannot = any of {2,:}
>
> What is the size of P? Is it a 1 x something cell array, each
> member of which is an array? Or is it a 2 x something cell array,
> each member of which is an array? When you write P{2,b} do
> you mean "the b'th column of the 2nd row of P", or do you mean
> "the b'th element of the array P{2}" ? If P is really a 2 x something
> cell array, P{2} is the same as P{2,1} .
> --
> Programming is what happens while you're busy making other plans.


the total size of P is N (e.g. 16) but can be split over a number of columns cells in any array i.e length of P{2} = N. its hard to explain but it based on permutations so each cell may be a different size.

for P{2,b} i mean the b'th column of the 2nd row of P

have to change the code around a bit to use :
find( ~ismember( 0:N-1, P{2} ), 1 )
so il keep you updated

thanks