Problem with function

There are prblems when displaying function ln(sin(x)/x).

;This file was created by Graph (http://www.padowan.dk)
;Do not change this file from other programs.
[Graph]
Version = 4.3.0.384
MinVersion = 2.5
OS = Windows NT 6.0 Service Pack 1

[Axes]
xMin = -21.5598244126961
xMax = 35.0087180873039
xTickUnit = 3.14159265358979
xGridUnit = 3.14159265358979
xMultiplyOfPi = 1
yMin = -32.6079815047771
yMax = 23.9605609952229
yTickUnit = 5
yGridUnit = 5
AxesColor = clBlue
GridColor = 0x00FF9999
ShowLegend = 1
Radian = 1

[Func1]
FuncType = 0
y = ln(sin(x)/x)
Color = clRed

Re: Problem with function

testplast <at> o2.pl wrote:
> There are prblems when displaying function ln(sin(x)/x).

The reason is that the function is so steep that Graph cannot handle it. 
It often helps to tell Graph to use more steps, but in this case I think 
you you need too many steps. I am looking at implementing another 
algorithm that should enable Graph to plot this kind of function correctly.

Best regards
Ivan Johansen

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Re: Problem with function

Well, I tried Maxima, GeoGebra och Graphmatica with the same function 
and they all have problems with that particulary one.

Best, Thomas

 2009-01-20 18:34, Ivan Johansen skrev:
> testplast <at> o2.pl wrote:
>   
>> There are prblems when displaying function ln(sin(x)/x).
>>     
>
> The reason is that the function is so steep that Graph cannot handle it. 
> It often helps to tell Graph to use more steps, but in this case I think 
> you you need too many steps. I am looking at implementing another 
> algorithm that should enable Graph to plot this kind of function correctly.
>
> Best regards
> Ivan Johansen
>
>
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> SourcForge Community
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>   

Problem with function

But Graph sometimes displays it correctly and sometimes not.
I found that problem when i first drawn this function. It was displayed 
correctly. When i moved the graph it was not correct anynmore. I moved a 
little and once good, once bad...

On the support page tgere is:

To post a message to the list, send an email to graph-
support <at> lists.sourceforge.net

It is how it is displayed on firefox's standard font settings.
When somebody (me :-D) uses email adresses from webpages by copying them 
rather by clicking on link, he/she might copy support <at> lists.sourceforge.net

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Re: Problem with function

testplast <at> o2.pl wrote:
> But Graph sometimes displays it correctly and sometimes not.
> I found that problem when i first drawn this function. It was displayed 
> correctly. When i moved the graph it was not correct anynmore. I moved a 
> little and once good, once bad...

This happens because the function is very steep. So it depends on which 
values Graph tries to evaluate the function for. It probably helps to 
zoom in on the function.

> On the support page tgere is:
> 
> To post a message to the list, send an email to graph-
> support <at> lists.sourceforge.net
> 
> It is how it is displayed on firefox's standard font settings.
> When somebody (me :-D) uses email adresses from webpages by copying them 
> rather by clicking on link, he/she might copy support <at> lists.sourceforge.net

Fortunately that is easy to fix. I have added a line break now.

Best regards
Ivan Johansen

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Asymptote in Graph

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Re: Asymptote in Graph

Christoffer Simoni wrote:
> I have a problem with Graph, and i am hopeful that you will be able to 
> help me. How do I plot in an asymptote for a x-value that the function 
> is not defined for. When i try to, an error occur telling me that i cant 
> because of division by 0.

I am not exactly sure what you are trying. But you can create a vertical 
line as a parametric function, e.g. x(t)=5, y(t)=t

Best regards
Ivan Johansen

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Re: Asymptote in Graph

 2009-01-29 21:51, Ivan Johansen skrev:
> Christoffer Simoni wrote:
>   
>> I have a problem with Graph, and i am hopeful that you will be able to 
>> help me. How do I plot in an asymptote for a x-value that the function 
>> is not defined for. When i try to, an error occur telling me that i cant 
>> because of division by 0.
>>     
>
> I am not exactly sure what you are trying. But you can create a vertical 
> line as a parametric function, e.g. x(t)=5, y(t)=t
>
> Best regards
> Ivan Johansen
>
>   
Or as a relation x = 5.

-- 
Vänliga hälsningar/  Bedste hilsner/  Best regards/  Bien cordialement/  Cordilamente/  Pozdrowienia/ 
Schöne Grüße/  Szívélyes üdvözlettel,  Thomas 

*******************************************************
Thomas Lingefjärd

Associate Professor, Mathematics Education
UNIVERSITY of GOTHENBURG, Department of Education

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Re: Asymptote in Graph

Christoffer Simoni <simoni75 <at> hotmail.com> writes:

> 
> 
> Hello!   I have a problem with Graph, and i am hopeful that you will be able
to help me. How do I plot in an asymptote for a x-value that the function is not
defined for. When i try to, an error occur telling me that i cant because of
division by 0.  - ChristofferBold - Babes og Gadgets! Alt på MSN Mand

> Der er jo ingen grund til at skrive på engelsk, har jeg så fundet ud af :) Det
jeg prøvede på var bare at plotte en asymptote for en polynomiumsbrøk ind. Den
pågældende brøk havde nævneren: x, og da jeg prøvede at indtegne asymptoten x=0
vha. den der evaluering kom den med fejlen: f(x): division med 0, hvilket jo
ganske vist er en naturlig reaktion. Men det virker glimrende når jeg bare
indtegner den på den måde du foreslog. Mange tak for hjælpen!
> 
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> 

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