Stratify Command

Response to query on ACL User Forum Dated May 5, 2006:

I'm attempting to run the stratify command on some data and I've set the interval to 1000 and the range from -15000 to 130000 which is appropriate for the data.  When ACL finishes stratifying, it comes back with random intervals, usually around 144 or so which results in far too many for what I'm trying to do.

ACL is doing exactly what you've asked it to do.  You have given it a range of -15,000 and 130,000.  You then asked it for 1000 intervals---not a spacing of a thousand.  EG, if you had a range of 1-1000 and you wanted a break down in 100's (1-100, 101-200, 201-300, etc), you would not put 100 in the interval value, but rather 10.  10 would tell the system to break the range into ten equal values of 100.  Does that make sense?

So, if you want ranges of 1000, you would need to set the interval at 144 (and you probably want to change the -15,000 to -14,999.)  (EDIT: I tested this, you need to set the interval at 145.)

Another option, depending on what you are trying to do, would be to set up free ranges.  This would allow you to establish parameters/thresholds such as:
    -15000 to 0                
              1 to 10,000
    10,001 to 25,000
    25,001 to 50,000
    50,001 to 100,000
    100,001 to 130,000
I often find the "Free" option to be much more beneficial when stratifying data (but again, it depends on what you are looking for.)

*HINT* When using the Free button, you may find that you want to modify what you've entered, but you don't want to type everything into the system again.  EG you decide you want to add another range to the above at 75,000.  Bring up the command on the command line (you can either do this via the Log or if you have the stratification on the screen by hitting the command.)  When the command is on the command line, you can hit the small white box with blue border and this will bring up the ranges you had previously selected.