The current version of Istar has a number of limitations. Some of them
include:
# Cannot import to KB from another KB.
# The FIRSTOK inference method (Present Each To User) not yet
implemented.
# Cannot use the Import-Text yet on items.
# Cannot at present delete value names from an attribute type; can only
add them.
# Certain obscure conversions between value types do not work fully; best
to try them out before you use them. e.g. Float to Odds.
# The new text/document facility is at present very limited.
This is a list of some bugs you should be aware of.
# (Only in the early version of v1.08 uploaded around Christmas 1997:
Occasional Crash; the real version, uploaded 3-Jan-98 should be OK) If you
tried to change the attribute value type on the attribute details panel it
could crash. Caused by calling a routine with parameters the wrong way
round. Action: Download the new version, or avoid changing value type.
# (Only in the early version of v1.08 uploaded around Christmas 1997:
Minor Nuisance; the real version, uploaded 3-Jan-98 should be OK) In new
KBs the attribute given to Text Fragment and Insert item types are wrong.
# (Harmless nuisance) If you start to create a new item type (and
relationship type) then hit 'Cancel' the type is not actually deleted; you
get a type with a null (dash) name and have to hit the 'Rid' button to
remove it. This is because it first creates a null-named type and then
allows you to change its details.
# (Can be misleading to user) The explanation of a relationship type is
only accurate for simple types; the facility is yet to be finalized.
Version 1.04 and earlier.
# (Nuisance) Recently I had things like DirOpus loaded, and went to load
up three KBs with full size easels. Then tried to 'rid' a KB and nothing
happened. Tried to quit and nothing happened. Because I had run out of
Chip memory and the small "Is it OK to rid the KB?" panel would not come
up! (Chip memory was down to 13k.) But beware: there is no warning, and
none can be given because the warning panel will not come up.
# (Harmless limitation) Various buttons are not operative yet:
# (Harmless limitation) Conversion Float to Odds does not work.
# (Could lead to unexpected results in your KB) When a conversion does
not work you do not get any warning of this fact. What happens depends on
the type of conversion, but often the result holds the bit pattern of the
uncoverted value, which might of course seem like rubbish, or might hold 0.
30 July 1996.
(Please: it you have it crash on you, send me details.
Istar@basden.demon.co.uk). The following crashes I have experienced and
not yet found the cause of.
# (1.04: Probably OK from 1.05. Can cause crash, but avoidable) The
resize KB facility can be a bit fragile and can cause a crash in version
1.04. This is because if the KB increases in size it moves in memory and
therefore all the pointers into it must all be changed. I *think* I have
found all these, but I did once get a guru 81---5 (attempt to free memory
already freed) when I quit the program. I have a feeling it was something
to do with resizing. For this reason, before you attempt to resize you
should close down all panels except that for the KB itself.
# (Cosmetic, harmless; PARTLY FIXED) Version 1.02: A Form item does not
space out the value gadgets properly always. Some of them are too tall and
overlap others. 2 August 1996. This is being investigated. It has been
partly cured (still untidy) in Version 1.03.
# (Nuisance to end user in versions 1.05 and earlier) The Chooser
inference method would only reset its attribute to unanswered every other
time, not every time. A bug in dealing with first (index) antecedent.
Fixed after 1.05.
# (Nuisance in version 1.04, corrected 1.041) A bug entered V1.04 that I
found two days after placing it on Aminet! It would not allow you to
change value types in the Attribute Details panel. Immediately corrected
it and placed new version 1.041 on Aminet.
# Bug when adding new attribute to items with shown attributes. The new
one would be placed on top of old one. Now it's OK; they are placed in a
vertical column.
# (A freeze if not a crash!) There's an odd sort of bug when Istar runs
up on some machines. It's perfectly OK on the three 1200s that I have
tried it on (020 and 030). But when I run it up on my 4000 it comes up
with the main easel and the SIT (Select Item Type) panel and all, but won't
draw, and won't respond to clicks on the main control panel. Until, that
is, I click around on the SIT panel. Sometimes dragging the listview
scroll bar around helps, and then clicking to select an item type,
sometimes clicking on the 'New' button. Then there is a delay of a few
seconds, and everything starts as normal. Strange. But, as I say, on my
three 1200s it seems perfectly OK. 9.9.96: I have found a possible cause
of this and corrected it, but have yet to try it out. No, it does not work
yet, Nov 1996. I got an email to say that it froze their 3000 too. While
preparing 1.05 I found a slight error in the code, changed it, and then it
seemed to work on my 4000 and 3000. So hopefully it's now OK.
# (Harmless Cosmetic) When you change the name of an item, it doesn't
redraw with the new name until F1 or next load. Attribute names refresh
OK. Version 1.03 and before.
# (Harmless Nuisance) When trying to resize an item using right-shift,
you have to place the mouse *exactly* on the edge of the box: hit-vicinity
is zero. Otherwise you will start to draw a link or move the box; if that
happens then just hit escape. Version 1.03 and before. (Actually, it was
not the need for exact positioning: it required a second attempt. A bug in
window switching.)
# (Harmless cosmetic) When you start drawing on the main easel and abort
by hitting escape you get a beep-flash. Don't worry: nothing is wrong.
Version 1.03 and before.
# (Harmless nuisance) New facility in Version 1.03, Resizing of KBA,
doesn't work; it leaves the KBA as it is.
# (Harmless nuisance) The Backup button on the KB Area panel (Version
1.03) has no effect.
# (Harmless cosmetic nuisance) Renaming the KB Area sometimes leaves
rubbish characters at the end. Version 1.03.
# (Harmless, cosmetic) When you reset an attribute that is in the middle
of a network it propagates the unanswered status OK, but does not show this
change in status on the easel. So if the Att is e.g. Bayesian and Shown it
retains the solid black line.
# (Frustrating but probably harmless) Version 1.03: When you have two
KBs active, and go to the Item Type Panel, and hit the Left or Right
RelTypes buttons nothing happens. But when you get rid of all but one then
the list of RelTypes appears OK. 5 August 1996. This is being
investigated.
# FIXED. Version 1.02: Never press the three right hand gadgets of the
name/meaning bar unless a knowledge base is present. It will probably
crash the machine or send it into an infinite loop since they assume one is
present. 2 August 1996. This has been corrected in version 1.03.
# Version 1.02: When redirecting a link the DAG cycle detection algorithm
sometimes says there is a loop when there is not. 2 August 1996. This is
being investigated. 12 September 1996: I have found the bug: it
occasionally searched from the wrong node. Now it should be OK in Version
1.03.
# Version 1.02. It occasionally crashed while linking two items. I have
found a bug that could do this, and corrected it. Version 1.03 should be
OK.
Copyright (c) Andrew
Basden 1997.