X
PrevPrev Go to previous topic
NextNext Go to next topic
Last Post 02 Dec 2015 05:19 PM by  anon
can WHERE function be maxed out?
 1 Replies
Sort:
You are not authorized to post a reply.
Author Messages

anon



New Member


Posts:7
New Member


--
02 Dec 2015 05:19 PM
    I am indexing large datasets (2239 by 880 pixels - not that large for remote sensing datasets) using the WHERE function, and counting the indexed pixels. My counts are clearly off, and I have the suspicion that the count cannot handle the large number. I read that count is a long integer, but googling I find conflicting information on the maximum number that a long integer can hold. Is there a way to get around this? Is it only the count that is a problem, or the indexing itself?

    Zachary Norman



    Basic Member


    Posts:173
    Basic Member


    --
    03 Dec 2015 10:18 AM
    Hello, The WHERE function returns a long array and the maximum allowable values for a long number are from -2,147,483,648 to +2,147,483,647. You can find that information at the following web page, which tells you a lot of information about all of the different IDL datatypes: http://www.exelisvis.com/.../IDL_Data_Types.html There is also a keyword for the WHERE function (the keyword is /L64) to return a 64bit long array which has values ranging from -9,223,372,036,854,775,808 to +9,223,372,036,854,775,807. I hope that helps! -Zach (VIS)
    You are not authorized to post a reply.

    Forums Products IDL