error while displaying a line

[z pekar gmail com]

I have to have autorescale on that place in my function. For the cases
when its no longer a line I get no error.
So where should I use the gtk_databox_set_total_limits? - autorescale
will anyway internally call the same function with the problematic
values and cause the warning...

so maybe we should enhance the autorescale function parameters list to
include 4 more:
gfloat left,gfloat right,gfloat top,gfloat bottom
to be used in case when a line is being displayed?

On Fri, Sep 26, 2008 at 10:11 AM, Eric Work <work eric gmail com> wrote:
> void gtk_databox_set_total_limits (GtkDatabox *box,
>                                   gfloat left,
>                                   gfloat right,
>                                   gfloat top,
>                                   gfloat bottom);
>
> This function is used to set the limits of the total display area of
> box. This function can be used to invert the orientation of the
> displayed graphs, e.g. top=-1000 and bottom=0.
>
> Side effect: The box also internally calls
> gtk_databox_set_visible_limits() with the same values.
>
> -Eric
>
> On Thu, Sep 25, 2008 at 1:13 PM,  <z pekar gmail com> wrote:
>> how can I set those values manually?
>>
>> On Fri, Sep 19, 2008 at 7:24 PM, Eric Work <work eric gmail com> wrote:
>>> Hey,
>>>
>>> I tend to think it would often incorrectly "guess" what the developer
>>> visually prefers, as with Alexey's example showing zero or not.  Also,
>>> do you show a range of +/-0.01 or +/-100 around the value?  These
>>> could be settings, a new struct argument containing bool zero_x, bool
>>> zero_y, int offset_x, int offset_y, with the default behavior
>>> undefined (passed a NULL pointer?) resulting in this error.  I feel
>>> you'd have to overwrite the default behavior quite often.  The
>>> developer might also benefit from having this error displayed as a
>>> warning; to possibly indicate an algorithm problem. The developer can
>>> also handle this error with a trivial if/else statement when they have
>>> specific needs.  One example: for an oscilloscope the user sets the
>>> desired volts/div so often you won't autoscale, but if you did
>>> autoscale it would be to allowable division sizes.
>>>
>>> That's my $0.02
>>>
>>> -Eric
>>>
>>> On Fri, Sep 19, 2008 at 2:25 AM,  <z pekar gmail com> wrote:
>>>> so maybe some default behavior should be implemented in order to avoid
>>>> the error output, and if the app. developer doesn't like it - he can
>>>> always rewrite it.
>>>>
>>>> On Fri, Sep 19, 2008 at 11:14 AM, Alexey Shuvaev
>>>> <shuvaev physik uni-wuerzburg de> wrote:
>>>>> On Thu, Sep 18, 2008 at 10:04:10PM +0200, Dr. Roland Bock wrote:
>>>>>> z pekar gmail com wrote:
>>>>>>> Hello,
>>>>>>> I get an error while displaying a line (parallel to x-achse; y(x) = c)
>>>>>>>
>>>>>>> gtk_databox_set_total_limits: assertion `left != right' failed
>>>>>>>
>>>>>>> what could it be?
>>>>>>> thank you
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> you are probably calling gtk_databox_auto_rescale?
>>>>>>
>>>>>> That function calculates
>>>>>>
>>>>>> (Pixel_max - Pixel_min)/(Value_max - Value_min)
>>>>>>
>>>>>> This fails for a line parallel to the x axis (and would also fail for a
>>>>>> line parallel to the y axis).
>>>>>>
>>>>>> Of course it would be possible to "guess" a useful data range. The
>>>>>> question is: What is the right heuristic, which seems natural for
>>>>>> viewers at different values?
>>>>>>
>>>>>> Solutions are welcome :-)
>>>>>>
>>>>> I don't think one can have a good "guess" for all cases.
>>>>> For example, when plotting some abstract mathematical function one may
>>>>> set y_scale = x_scale. On the other hand, in a physics application when
>>>>> x = time and y = voltage one may want to always include zero (y = 0) in
>>>>> the graph and to set y scale to full device range if the signal is
>>>>> a constant zero too.
>>>>>
>>>>> So, IMHO, the proper scaling is a responsibility of the application developer
>>>>> and not the library.
>>>>>
>>>>> Just my 0.02$,
>>>>> Alexey.
>>>>> _______________________________________________
>>>>> gtkdatabox-list mailing list
>>>>> gtkdatabox-list gnome org
>>>>> http://mail.gnome.org/mailman/listinfo/gtkdatabox-list
>>>>>
>>>> _______________________________________________
>>>> gtkdatabox-list mailing list
>>>> gtkdatabox-list gnome org
>>>> http://mail.gnome.org/mailman/listinfo/gtkdatabox-list
>>>>
>>>
>>
>