Re: Small technicality on dynarray

[Ethan A M. <merritt@u.washington.edu>]

On Saturday 30 June 2007 19:49, Daniel J Sebald wrote:
> Ethan A Merritt wrote:
> > On Saturday 30 June 2007 16:55, Daniel J Sebald wrote:
> > 
> >>>But why would you want to do this?
> >>
> >>So that the original data is not lost.  STORE_VALUE_WITH currently tosses the data.
> > 
> > 
> > It does not.
> > We are ignoring the log/unlog case, because it will go away.
> 
> It currently does.
> 
> 	if (VALUE<0.0) {						  \
> 	    TYPE = UNDEFINED;						  \
> 	    UNDEF_ACTION;						  \
> 	    break;							  \

Only for logscale data.  I said to ignore that.

> How will it go away?
> Are you saying that one will not be able to use mouse log/unlog scale 
> and "set logscale x", etc. unless the data file is present?

I am saying that totally separate from this patch, we should implement
a method of axis-scaling that is general enough to handle log scale as
just one more scaling operation.  When that is in place, input data will
be stored as read in, and the existing special case code for log scale
can go away.

> I punted ... mainly because that curve-fitting code that alters the data.  

I must have missed that. Where?

> I've come to the conclusion that saving the v's and j's is preferred.

I think I know what you mean by v[], but who are the j's?
Anyhow, I doubt it.  

Counter-example 1:  Consider the dumb but perfectly legal case of an input file
with 100 columns, and the command 'plot "foo" using ($1+$2+$3+...+$100)'
Why should we store all 100 columns, when only one value will be used?

Counter-example 2:  'splot "foo" using 1:2:(system("date")) with labels'
Not that it makes any sense to plot the date, but the point is you cannot
assume that the value of v[3] will be the same next time you execute the plot
command.  And if it isn't, then what have you gained by saving it?

> The j/v's solution is actually pretty solid because of the code clean up we've done.  
> Data can only come in through df_readline() and that is where we are tapping into things.  
> On refresh, just push the code through the very beginning of the system and it 
> doesn't matter if there was curve fitting code in between.   

Are you suggesting that the curve-fitting would be re-done, and perhaps change,
during a zoom operation?  That sounds highly undesirable to me.
And if it doesn't change, then why go back and do it again?

> >>There is quite of bit of code between reading it in and storing it.  
> > 
> > Please quote code sections.  I see none.
> 
> I meant between reading and plotting, sorry.  E.g., splines and who knows what else?

Code sections please.


-- 
Ethan A Merritt