Pulling my hair out over this simple for loop! Please help!

I keep getting the "subscripted assignment dimension mismatch" error. My variables are:

ia1=[79;91;94]
ia2=[80;103;95]
date = vector of datetimes (right below)
'08/25/2008'
'08/26/2008'
'08/27/2008'
'08/28/2008'
'08/29/2008'
'09/02/2008'
'09/03/2008'
'09/04/2008'
'09/05/2008'
'09/08/2008'
'09/09/2008'
'09/10/2008'
'09/11/2008'
'09/12/2008'
'09/15/2008'
'09/16/2008'
'09/17/2008'
'09/18/2008'
'09/19/2008'
'09/22/2008'
'09/23/2008'
'09/24/2008'
'09/25/2008'
'09/26/2008'
'09/29/2008'
'09/30/2008'
'10/01/2008'
'10/02/2008'
'10/03/2008'
'10/06/2008'
'10/07/2008'
'10/08/2008'
'10/09/2008'
'10/10/2008'
'10/13/2008'
'10/14/2008'
'10/15/2008'
'10/16/2008'
'10/17/2008'
'10/20/2008'
'10/21/2008'
'10/22/2008'
'10/23/2008'
'10/24/2008'
'10/27/2008'
'10/28/2008'
'10/29/2008'
'10/30/2008'
'10/31/2008'
'11/03/2008'
'11/04/2008'
'11/05/2008'
'11/06/2008'
'11/07/2008'
'11/10/2008'
'11/11/2008'
'11/12/2008'
'11/13/2008'
'11/14/2008'
'11/17/2008'
'11/18/2008'
'11/19/2008'
'11/20/2008'
'11/21/2008'
'11/24/2008'
'11/25/2008'
'11/26/2008'
'11/28/2008'
'12/01/2008'
'12/02/2008'
'12/03/2008'
'12/04/2008'
'12/05/2008'
'12/08/2008'
'12/09/2008'
'12/10/2008'
'12/11/2008'
'12/12/2008'
'12/15/2008'
'12/16/2008'
'12/17/2008'
'12/18/2008'
'12/19/2008'
'12/22/2008'
'12/23/2008'
'12/24/2008'
'12/26/2008'
'12/29/2008'
'12/30/2008'
'12/31/2008'
'01/02/2009'
'01/05/2009'
'01/06/2009'
'01/07/2009'
'01/08/2009'
'01/09/2009'
'01/12/2009'
'01/13/2009'
'01/14/2009'
'01/15/2009'
'01/16/2009'
'01/20/2009'
'01/21/2009'
'01/22/2009'
'01/23/2009'

Here is my loop:

for i = 1:length(ia1)
    trade(i)=date(ia1(i):ia2(i));
end

If I change the second line to

trade=date(ia1(i):ia2(i));

then the loop works, but it overrides the first two vectors and leaves just the last one.

I am extremely grateful for any help!

[Ahmet Cecen]

Cannot replicate the error with the pieces of codes you have given. Unless you share the entire code with the data, the best way to resolve a situation like this is to use dbstop. Go to your command line and write:

 dbstop if error

Then run your entire script using the play shaped run button in the editor or writing the name of the script in the command line and pressing enter.

The program will stop running at the exact moment you error is happening, with the values of every variable at the moment of the error. Hopefully you can figure out why the error is happening using that information. If you only have scripts and no functions this might not be of much help though.

[Cary]

I am using a script, I don't think I need a function for this. I already tried dbstop if error and couldn't resolve the issue. I am attaching the datetime vector to my original post. You should have everything you need to replicate this. Thanks :)

Answer 1

[Walter Roberson]

You need to initialize trade as cell, such as

trade = {};

Then in your loop you need

trade{i} = date(ia1(i):ia2(i));

You are extracting a number of datetime objects at the same time, so each date(ia1(i):ia2(i)) is going to produce a vector of datetime objects. You have been attempting to store that vector into a single location, trade(i) . Only cell arrays can store multiple values inside locations designated with a single index.

Later you will need to use {} notation to extract the vector of datetime objects when you want to use the vector.

Answer 2

[Ahmet Cecen]

Its the brackets. You cannot use normal brackets for vectors of strings as they are stored as cell arrays.

 for i = 1:length(ia1)
    trade{i}=date(ia1(i):ia2(i));
 end

Actually that is not the only thing, your vector size of dates for each i is different as well, so it wouldn't have worked either way.

[Cary]

I'm sorry, it's not vector of strings, it's a datetime vector. It just looked like a string when I pasted it into the thread. I tried the cell brackets..."Cell contents assignment to a non-cell array" error. Any other suggestions? Thanks so much.