RE: st: RE: Large data set that won't open

["Nick Cox" <n.j.cox@durham.ac.uk>]

Sure. There is a difference between -ls-, the Stata command, and -ls- as
an OS command or utility used outside Stata. 

In my experience, the routine use of -ls- usually signals a Unix mindset
if not a Unix machine. 

Nick 
n.j.cox@durham.ac.uk 

Martin Weiss

" I think that John signalled indirectly through an example using an
-ls- that he is using some flavour of Unix."


-ls- works on my Windows machine w/o problems, though...

Nick Cox

Also to the point: 

1. If the dataset is too big for Stata, it will hardly fit into Excel
(unless very recent versions of Excel have suddenly acquired greatly
increased capacities). 

2. I think that John signalled indirectly through an example using an
-ls- that he is using some flavour of Unix. In that case, he is unlikely
to have access to Excel any way. (Either way, everyone being clear about
what OS they are using assists communication in this area.) 

Nick 
n.j.cox@durham.ac.uk 

Martin Weiss

But why bother to use spreadsheets here, given that Stata can, as I
mentioned earlier, -use- part of a file? Apart from -if- and -in-, a
-varlist- can also be supplied, so the "split on variables" can be
achieved
within Stata.

Kay Walker

Possibly if you can't get into Stata to edit the data file to make it 
smaller, drop it into Excel, split the file on variables not cases,(and 
copy the identifiers to the "new" half)  so that you can analyse only 
those variables and cases you NEED in a particular context. You can 
always swap relevant variables in and out of the working data file if 
you want to perform further analyses later. I think it's the fact that 
the RAM has to hold the program and the relevant part of the datafile in

memory for analysis that is causing the problem, not merely the size of 
the datafile vs the program.

Martin Weiss wrote:

> The size of your RAM is hard to tell from your current memory
allocation -
> the latter is just a lower bound for the former. But I guess you do
not
have
> 6G of RAM, do you? You would still need additional RAM for
computations,
> then. 
>
> Note you can -use- a dataset with -if- and -in- qualifiers, so it is
still
> possible to get a subset into mem...

John Antonakis

> I have a rather large data set that I cannot open in Stata; here are
the 
> particulars:
>
> ls "D:\My Documents\STATA\upstata.dta",
> 5375.8M   6/23/10 10:44  upstata.dta  
>
> When I try to open the data set I get:
>
> . use "D:\My Documents\STATA\upstata.dta", clear
> no room to add more observations
>     An attempt was made to increase the number of observations beyond 
> what is currently
>     possible.  You have the following alternatives:
>
>      1.  Store your variables more efficiently; see help compress.  
> (Think of Stata's data
>          area as the area of a rectangle; Stata can trade off width
and 
> length.)
>
>      2.  Drop some variables or observations; see help drop.
>
>      3.  Increase the amount of memory allocated to the data area
using 
> the set memory
>          command; see help memory.
> r(901);
>
> Here is my current memory allocation:
>
> . q memory
>
> Current memory allocation
>
>                     current                                 memory
usage
>     settable          value     description                 (1M =
1024k)
>
--------------------------------------------------------------------
>     set maxvar         5000     max. variables allowed
1.909M
>     set memory         1024M    max. data space
1,024.000M
>     set matsize        1000     max. RHS vars in models
7.713M
>
-----------
>
1,033.622M
>
>
> It seems that I just don't have enough RAM to open this file.  Is that

> correct?

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