Re: conflict of separator and missing

[<pl...@pi...>]

On 14/06/16 12:52, Allin Cottrell wrote:
> On Tue, 14 Jun 2016, pl...@pi... wrote:
>
>> On 14/06/16 09:43, pl...@pi... wrote:
>>>
>>> I have a data csv datafile which uses -99.99 as it missing data value.
>>>
>>> with the following settings the 'missing' data are getting plotted.
>>>
>>>   set datafile separator ","
>>>   set datafile missing "-99.99"
>>>
>>>
>>>   show datafile missing
>>>
>>>          "-99.99" in datafile is interpreted as missing value
>>>
>>>
>>> As a wild guess I tried the following and the missing data now get
>>> correctly removed.
>>>
>>>   set datafile missing "-99.99,"
>>>
>>>
>>> This seems to be an illogical order of parsing.
>>>
>>> Surely the data line needs to be parsed into its constituent data
>>> columns before trying to detect the missing data string.
>>>
>>> Regards, Peter
>>>
>>>
>>> gnuplot> show version
>>>
>>>          G N U P L O T
>>>          Version 5.0 patchlevel 1    last modified 2015-06-07
>>>
>>>          Copyright (C) 1986-1993, 1998, 2004, 2007-2015
>>>          Thomas Williams, Colin Kelley and many others
>>>
>>>          gnuplot home:     http://www.gnuplot.info
>>>          faq, bugs, etc:   type "help FAQ"
>>>          immediate help:   type "help"  (plot window: hit 'h')
>>>
>>>
>>>
>>
>> Just to complete this here is a sample line from the file displaying
>> this bug.
>>
>> 1958, 06,   21351, 1958.4548,   -99.99,   -99.99,     317.25,   315.14,
>>    317.25,   315.14
>
> Doesn't it invite undefined behavior if you set "," as separator but
> then also include spaces between the values?
>
> Allin Cottrell
>

I'm not including anything, I have some data provided that I need to 
plot with gnuplot.
I've always found gnuplot smart enough to deal with most things that 
I've thrown at it. If this is not a bug I could always preprocess the 
data to remove the commas.

The question remains as to whether this is a bug or not.

The fourth field in that line is "  -99.99" when using comma separator.

This data is supplied with a missing VALUE of -99.99 . Will this match 
gnuplot's datafile missing defined as a string "-99.99"  ?  That depends 
upon how the equality test is done in a language that has fuzzy 
variable types.

But that does not account for the behaviour of it working with datafile 
missing set to "-99.99,"

That seems to clearly indicate that there is logical problem here. The 
comma should no longer be there in the data field since it is the field 
separator.

Peter.