The number of rows and columns in Excel 2007 is the addressable capacity--17 billion cells. load'format' xfmt"0] 2^20 14 NB. rows columns 1 048 576 16 384 xfmt"0] */2^20 14 17 179 869 184
However, usable memory is limited to 2Gb, which is the same as in any regular 32-bit application. Given the cell formatting and other overhead, it could be assumed that if Excel can handle a given file, J should also be able to, without even using mapped files. Improving Performance in Excel 2007 http://msdn2.microsoft.com/en-us/library/aa730921.aspx --- On Mon, 4/21/08, Devon McCormick <[EMAIL PROTECTED]> wrote: > FWIW - since I have Excel 2007 installed on one of my > machines, I thought > I'd mention that its row and column limits are 1048576 > x 16384. > > I kept running out of memory trying to use Tara to write my > 65536 by 256 > matrix of floating point numbers to a spreadsheet. I also > had problems > using OLE but was able to do it in pieces (about 16K rows > at a time) in > about 1 minute (on a 2.66 GHz machine with 2 GB RAM). > I'm sure it could be > done in Tara much the same way (possibly more quickly) but > I'm not familiar > with that package. > > On 4/21/08, Sherlock, Ric <[EMAIL PROTECTED]> > wrote: > > > > Amit, > > >From the thread you started on comp.lang.apl it > seems that your files are > > only about 50,000 rows. As Richard suggested in that > thread - that isn't > > very big. You shouldn't have to resort to > memory-mapped files for something > > that big. If you just want to import the data from the > Excel spreadsheet and > > then work with it in J then I wouldn't imagine > that will present too much of > > a problem. > > > > I just used the Tara addon for J to create an Excel > workbook with a sheet > > containing 50,000 rows and 10 columns. I then used > Tara to read that data > > from the Excel worksheet back into J. > > > > Importing (reading) the file into J took a number of > seconds using Tara, > > but once the array was in J, I was able to operate on > the whole (or parts of > > the) array quickly and easily. For example getting the > sum of all 10 columns > > over the 50,000 rows of the resulting array took > 0.0057 seconds in J. > > > ... > > > -- > Devon McCormick, CFA > ^me^ at acm. > org is my > preferred e-mail > ---------------------------------------------------------------------- > For information about J forums see > http://www.jsoftware.com/forums.htm ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
