q:how are decimal places calculated on Y-axis? (how to influence)?

[Pablo Sanchez-2]

Howdy,

I have a barometric graph which can display results in hPA or inHG.  I
store the data in hPA and use a CDEF to convert it to inHG when
requested.

My problem is that for the graph period, the `inHG' value may vary
only slightly:

     max:  29.97
     min:  29.88

I've tinkered with `--y-grid' to get better grid steps (before I was
only getting one line at 30 and the resulting graphed line was very
flat.  :):

   --y-grid .01:5

and the line graphs very well.  However, the y-axis labels seem to be
rounded.  Here's an example of what I see versus what I'd like:

    Wanted     Rendered
    ------     --------
    30.05         30
    30.00         30
    29.95         30
    29.90         30
    29.85         30
    29.80         30

I've tried using the `--alt-y-grid' option but that didn't help.

I'm using a very old version of RRD on this weather-station laptop:
1.2.23

Am I missing an obvious `rrdtool graph' switch or is this a bug in
this very old version of RRD?  :)

Please advise.

Note, I tried compiling the 1.3 version on this openSUSE 10.3 machine
and it resulted with no data being logged.  Quite strange.  So I went
back to thee 1.2.23 version - I even disabled nmap ...

Cheers,
--
Pablo Sanchez - Blueoak Database Engineering, Inc
Ph:    819.459.1926      Fax:   [phone] (US)

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Alex van den Bogaerdt-2]

----- Original Message -----
From: "Pablo Sanchez" <pablo@...>
To: <rrd-users@...>
Sent: Friday, June 19, 2009 6:04 PM
Subject: [rrd-users] q:how are decimal places calculated on Y-axis? (how
toinfluence)?

> and the line graphs very well.  However, the y-axis labels seem to be
> rounded.  Here's an example of what I see versus what I'd like:
>
>    Wanted     Rendered
>    ------     --------
>    30.05         30
>    30.00         30
>    29.95         30
>    29.90         30
>    29.85         30
>    29.80         30
>
> I've tried using the `--alt-y-grid' option but that didn't help.
>
> I'm using a very old version of RRD on this weather-station laptop:
> 1.2.23
>
> Am I missing an obvious `rrdtool graph' switch or is this a bug in
> this very old version of RRD?  :)
>
> Please advise.
>
> Note, I tried compiling the 1.3 version on this openSUSE 10.3 machine
> and it resulted with no data being logged.  Quite strange.  So I went
> back to thee 1.2.23 version - I even disabled nmap ...

Maybe try this one?

-L|--units-length value

Don't know when it was introduced, you may need to upgrade. Try another
1.2.xx instead of 1.3.xx


HTH
Alex

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Pablo Sanchez-2]

[ Comments below, in line ]

On Friday 19 June 2009 at 12:23 pm, Alex van den Bogaerdt penned
about "Re: [rrd-users] q:how are decimal places calculated on Y-axis? (how toinfluence)?"


> Maybe try this one?
>
> -L|--units-length value

Hi Alex,

I tried it but it didn't work.

> Don't know when it was introduced, you may need to upgrade. Try another
> 1.2.xx instead of 1.3.xx

I'll go hunt for another 1.2.xx

Thank you for your response.

Cheers,
--
Pablo Sanchez - Blueoak Database Engineering, Inc
Ph:    819.459.1926      Fax:   [phone] (US)

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Tobias Oetiker-3]

Hi Pablo,

Today Pablo Sanchez wrote:

> Howdy,
>
> I have a barometric graph which can display results in hPA or inHG.  I
> store the data in hPA and use a CDEF to convert it to inHG when
> requested.
>
> My problem is that for the graph period, the `inHG' value may vary
> only slightly:
>
>      max:  29.97
>      min:  29.88
>
> I've tinkered with `--y-grid' to get better grid steps (before I was
> only getting one line at 30 and the resulting graphed line was very
> flat.  :):
>
>    --y-grid .01:5
>
> and the line graphs very well.  However, the y-axis labels seem to be
> rounded.  Here's an example of what I see versus what I'd like:
>
>     Wanted     Rendered
>     ------     --------
>     30.05         30
>     30.00         30
>     29.95         30
>     29.90         30
>     29.85         30
>     29.80         30
>
> I've tried using the `--alt-y-grid' option but that didn't help.
>
> I'm using a very old version of RRD on this weather-station laptop:
> 1.2.23
>
> Am I missing an obvious `rrdtool graph' switch or is this a bug in
> this very old version of RRD?  :)
>
> Please advise.
>
> Note, I tried compiling the 1.3 version on this openSUSE 10.3 machine
> and it resulted with no data being logged.  Quite strange.  So I went
> back to thee 1.2.23 version - I even disabled nmap ...

the design goal of the yaxis numbering is that there should not be
more than 3 digits displayed this means that for 1-9 you will see
1.1 to 9.9 but from 10 on you will see no post comma digits ...

using --alt-y-grid should help in your case I guess ... but it
could be that it was broken in 1.2.23 ... if you want to stick to
1.2 you may want to try 1.2.30

cheers
tobi


> Cheers,
>

--
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi@... ++41 62 775 9902 / sb: -9900

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Pablo Sanchez-2]

[ Comments below, in line ]

On Friday 19 June 2009 at 1:14 pm, Tobias Oetiker penned
about "Re: [rrd-users] q:how are decimal places calculated on Y-axis? (how to influence)?"

> Hi Pablo,

Hi Tobi,

> the design goal of the yaxis numbering is that there should not be
> more than 3 digits displayed this means that for 1-9 you will see
> 1.1 to 9.9 but from 10 on you will see no post comma digits ...

Ah!  That explains it.  Okay.  Now I have something to go on.  Thank
you.

> using --alt-y-grid should help in your case I guess ... but it
> could be that it was broken in 1.2.23 ... if you want to stick to
> 1.2 you may want to try 1.2.30

I'll see if I can hunt down 1.2.30

Thank you again.

Cheers,
--
Pablo Sanchez - Blueoak Database Engineering, Inc
Ph:    819.459.1926      Fax:   [phone] (US)

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Alex van den Bogaerdt-2]

----- Original Message -----
From: "Pablo Sanchez" <pablo@...>
To: <rrd-users@...>
Sent: Friday, June 19, 2009 6:04 PM
Subject: [rrd-users] q:how are decimal places calculated on Y-axis? (how
toinfluence)?

> Howdy,
>
> I have a barometric graph which can display results in hPA or inHG.  I
> store the data in hPA and use a CDEF to convert it to inHG when
> requested.
>
> My problem is that for the graph period, the `inHG' value may vary
> only slightly:
>
>     max:  29.97
>     min:  29.88
>
> I've tinkered with `--y-grid' to get better grid steps (before I was
> only getting one line at 30 and the resulting graphed line was very
> flat.  :):
>
>   --y-grid .01:5
>
> and the line graphs very well.  However, the y-axis labels seem to be
> rounded.  Here's an example of what I see versus what I'd like:
>
>    Wanted     Rendered
>    ------     --------
>    30.05         30
>    30.00         30
>    29.95         30
>    29.90         30
>    29.85         30
>    29.80         30
>
> I've tried using the `--alt-y-grid' option but that didn't help.
>
> I'm using a very old version of RRD on this weather-station laptop:
> 1.2.23
>
> Am I missing an obvious `rrdtool graph' switch or is this a bug in
> this very old version of RRD?  :)

I got intrigued by this question and I just knew I've seen this happen in
the past. I found version 1.2.23 on my antique fedora machine and wrote this
small script. Try it.

rrdtool create test.rrd --start 1245448800 DS:test:GAUGE:300:U:U
RRA:AVERAGE:0:1:10

rrdtool update test.rrd 1245449100:29.97
rrdtool update test.rrd 1245449400:29.96
rrdtool update test.rrd 1245449700:29.95
rrdtool update test.rrd 1245450000:29.94
rrdtool update test.rrd 1245450300:29.95
rrdtool update test.rrd 1245450600:29.96
rrdtool update test.rrd 1245450900:29.97
rrdtool update test.rrd 1245451200:29.98
rrdtool update test.rrd 1245451500:29.99

set `rrdtool graph whatever DEF:test=test.rrd:test:AVERAGE
PRINT:test:MIN:%6.2lf PRINT:test:MAX:%6.2lf`

rrdtool graph test.png --start 1245448800 --end 1245451500 \
        --title "min $2 max $3" \
        --lower-limit $2 \
        --upper-limit $3 \
        --rigid \
        --alt-y-grid \
        DEF:test=test.rrd:test:AVERAGE \
        LINE1:test#FF0000:test


Both alt-y-grid and rigid seem to be necessary, my initial suggestion of
using -L was not.

If you don't need the scale to be 'dynamic', you can leave out that 1st
rrdtool command and just use fixed numbers in the 2nd call.

HTH
Alex

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Alex van den Bogaerdt-2]

> If you don't need the scale to be 'dynamic', you can leave out that 1st
> rrdtool command and just use fixed numbers in the 2nd call.


Replace "that 1st rrdtool command" with "the command starting with set", and
"2nd" with "final".

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Pablo Sanchez-2]

[ Comments below, in line ]

On Saturday 20 June 2009 at 5:35 am, Alex van den Bogaerdt penned
about "Re: [rrd-users] q:how are decimal places calculated on Y-axis? (how toinfluence)?"

> [ snipped]
>
> HTH

HTH - indeed!  Thank you Alex.  That got me going.  I had attempted to
fiddle with both `--y-grid' and `--alt-y-grid' and the mix was
`deadly'  <g>  It didn't occur to me to try `--rigid'  There's a
slight drawing error in the `monthly' graph (the `29.7' looks munged)
but I'm not going to worry about it.  :p

   [http://weather.hillsandlakes.com/wxgraphs-month_i.php]

Thank you again!

Cheers,
--
Pablo Sanchez - Blueoak Database Engineering, Inc
Ph:    819.459.1926      Fax:   [phone] (US)

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Pablo Sanchez-2]

[ Comments below, in line ]

On Saturday 20 June 2009 at 5:42 pm, Pablo Sanchez penned
about "Re: [rrd-users] q:how are decimal places calculated on Y-axis? (how toinfluence)?"

> [ http://weather.hillsandlakes.com/wxgraphs-month_i.php ]
>

I'm monitoring my Apache log file looking for errors as I'm tweaking
my graphs and I noticed some mail clients aren't stripping the
brackets ... I've added spaces to help.  :p

Cheers,
--
Pablo Sanchez - Blueoak Database Engineering, Inc
Ph:    819.459.1926      Fax:   [phone] (US)

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Pablo Sanchez-2]

[ Comments below, in line ]

On Saturday 20 June 2009 at 5:42 pm, Pablo Sanchez penned
about "Re: [rrd-users] q:how are decimal places calculated on Y-axis? (how toinfluence)?"

> There's a slight drawing error in the `monthly' graph (the `29.7'
> looks munged) but I'm not going to worry about it.  :p
>

Hi Alex,

I had upgraded to a later version (1.2.27) of `rrdtool' per Tobi's
suggestion.  I downgraded back to 1.2.23 and that fixed the issue
above.

Thank you again.

Cheers,
--
Pablo Sanchez - Blueoak Database Engineering, Inc
Ph:    819.459.1926      Fax:   [phone] (US)

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Reinhard Scheck]

Am 21.06.2009 02:55, Pablo Sanchez wrote:
> [ Comments below, in line ]
>
> Hi Alex,
>
> I had upgraded to a later version (1.2.27) of `rrdtool' per Tobi's
> suggestion.  I downgraded back to 1.2.23 and that fixed the issue
> above.

I'm using rrdtool 1.3.8 and have documented the results of this discussion here:
http://docs.cacti.net/manual:087:8_rrdtool.06_alt_y_grid

1.3.8 does _not_ require usage of upper/lower limit for best results

Reinhard

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users

[Pablo Sanchez-2]

[ Comments below, in line ]

On Sunday 21 June 2009 at 6:17 am, Reinhard Scheck penned
about "Re: [rrd-users] q:how are decimal places calculated on Y-axis? (how toinfluence)?"

> Am 21.06.2009 02:55, Pablo Sanchez wrote:
> > [ Comments below, in line ]
> >
> > Hi Alex,
> >
> > I had upgraded to a later version (1.2.27) of `rrdtool' per Tobi's
> > suggestion.  I downgraded back to 1.2.23 and that fixed the issue
> > above.
>
> I'm using rrdtool 1.3.8 and have documented the results of this discussion here:
> http://docs.cacti.net/manual:087:8_rrdtool.06_alt_y_grid

Thank you Reinhard -- good finds!  I've rolled the minor tweak you
found into my graphs.  

> 1.3.8 does _not_ require usage of upper/lower limit for best results

Neither does 1.2.23

Cheers,
--
Pablo Sanchez - Blueoak Database Engineering, Inc
Ph:    819.459.1926      Fax:   [phone] (US)

_______________________________________________
rrd-users mailing list
rrd-users@...
https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users