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From: bhoughto@pima.intel.com (Blair P. Houghton)
Newsgroups: comp.lang.c
Subject: Re: FLOATING NULL?
Message-ID: <4460@inews.intel.com>
Date: 29 May 91 02:08:23 GMT
Article-I.D.: inews.4460
References: <13223@uhccux.uhcc.Hawaii.Edu> <1991May28.153655.24199@zoo.toronto.edu>
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In article <1991May28.153655.24199@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <13223@uhccux.uhcc.Hawaii.Edu> karl@wiliki.UUCP (Karl Ihrig) writes:
>>...blank spots in my real world data.  I am totally baffled.  How do I
>>mark the float element of the array as null, blank, or not
>>available?
>
>There is no portable way except allocating a separate flag for each of
>your float values.  C does not guarantee the existence of any "blank" value

Another idea is to keep the 2-d array of floating point
numbers, and in the spreadsheet cells keep pointers to the
members of the array.  Then you can use a null pointer to
indicate a blank cell.

This roughly doubles the memory usage of that array, and
complicates a considerable amount of your floating-point
computations with pointer references, but it does provide
the important feature you desire.

				--Blair
				  "There's got to be a way
				   to get back homeward..."
				   -Lennon & McCartney