Re: MISSING and UNDEFINED

[Daniel J S. <dan...@ie...>]

Daniel J Sebald wrote:

> I still am wondering if there is a purpose to having both a datafile 
> missing string and datafile undefined string.  Somehow it seems to me 
> the user could have both such items at the same time and want there to 
> be different behavior based upon type.

Oh yeah, that question and also, if you look at the PNG's of the previous email, there is the question of a the line number (or datum) being incremented even when the data point is missing.  Are there some situation where that is undesirable?  For example, if you look at some of the histogram examples in all.dem, you might imagine a table like

"day of week"  "number of coots on lake"
"Monday"  127
"Tuesday"   N/A
"Wednesday"   35
"Thursday"  42
"Friday"  73

where the user may not want an empty blank space between the first and second histogram element.  (In some sense this illustrates the reason for df_readascii() to always return something if it finds a data point rather than ignoring DF_MISSING.  So the higher level routines can have alternative behavior in the future.)

Dan