are the first 3 elements of a vector NaN?

Dear all,I have

A={

 [NaN]
    [NaN]
    [NaN]
         [3]
    [3]
    [6]
    [4]}

I want to find a rule that will tell me if the first 3 elements of a vector A are NaN or not

thanks

[Yash]

you can apply condition on them

[Sabbas]

coul;d you please be more specific?

Answer 1

[Matt Fig]

A is a cell.

all(cellfun(@isnan,A(1:3)))

Answer 2

[Image Analyst]

Method 1. Inspects the first three cells ONLY.

A = {  
[NaN]
[NaN]
[NaN]
[3]
[3]
[6]
[4]}
if isnan(A{1}) && isnan(A{2}) && isnan(A{3})
  uiwait(msgbox('The first three cells are nans'));
else
  uiwait(msgbox('The are not nans.'));
end

Method 2. Somewhat more robust and flexible.

% Define starting and ending cell to inspect.
firstElementToCheck = 1;
lastElementToCheck = 3;
nanLocations = isnan([A{:}])
if sum(nanLocations(firstElementToCheck:lastElementToCheck)) == (lastElementToCheck - firstElementToCheck) + 1
  message = sprintf('The cells between %d and %d are all NaNs', ...
    firstElementToCheck, lastElementToCheck);
  uiwait(msgbox(message));
else
  message = sprintf('The cells between %d and %d are NOT ALL NaNs', ...
    firstElementToCheck, lastElementToCheck);
  uiwait(msgbox(message));
end