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From: wehr@fmsrl7.UUCP (Bruce Wehr )
Newsgroups: comp.sys.hp
Subject: BASIC bug? (was Re: BASIC/HFS/long file name systems)
Message-ID: <40235@fmsrl7.UUCP>
Date: 15 Apr 91 16:00:12 GMT
Organization: Ford Motor Company, Scientific Research Labs, Daerborn, MI
Lines: 39

Speaking of BASIC (yeah ... it looks like it'll be tough completely
ousting good ol' RMB for HP-UX in these labs :-)

We don't have BASIC 6.0 ... we're using 5.13. I have come across a bug
(WHAT!! ... in RMB?! Well, ... maybe).

I've put together some general purpose plotting software to look at
data acquired from the lab (an automotive test lab). Given some data,
the X and Y limits can be set by the user, or "autoscaled".

A particular test produces numbers in the 1E-3 range across numerous
samples. But this test can be pretty harsh, and occasionally sensors
fail.  Failed sensors produce numbers in the 1E+14 range. When the plot
for such a sensor is "autoscaled", it is scaled to show all the data -
but the scale is too large to see the detailed data that was acquired
before the failure. When the plot has the limits manually set to more
appropriate values, an "ERROR 19 - Improper value or out of range"
error is generated by the PLOT statement.

I've read the documentation on the PLOT statement. It says that its
arguments can be any real value (+-E308). I'm using BASICs own WINDOW
statement for mapping (it's much more efficient). It claims that any
value plotted outside the window will be ignored.  That's all it says -
implying again that any real value can be specified. However, it seems
that this error occurs when the an argument to the PLOT statement
exceeds about 5E+5 times the range of the window.

For now, I'm working around this by having the plot loop check the
value of the data before it plots it. If I understand the manuals
correctly, it shouldn't have to do this. Is this a bug, or am I missing
something? If it is a bug, has BASIC 6.0 addressed it?

Thanks for any enlightenment.

-- 
               Bruce Wehr (wehr%dptc.decnet@srlvx0.srl.ford.com)
                (..!uunet!srlvx0.srl.ford.com!wehr%dptc.decnet)
              Ford Motor Company - Engineering Technology Services
     P.O. Box 2053, Room 1153, Dearborn, Michigan 48121-2053 (313)337-5304