gnuplot-info

[Gnuplot-info] 3D function

[Zhong R. <re...@uc...>]

Hi,

I have a 3D function f(x, y, z) in form of a data file of 4
columns x, y, z, and f.  The distribution of the function
value f is symmetrical around 0 following a normal
distribution.  What is the best way to represent this kind of
data in Gnuplot?  Is there any example I can reference?  Some
software uses 3D net to represent contour surfaces.  Thanks
for any suggestions.

Zhong

Re: [Gnuplot-info] 3D function

[Hans-Bernhard B. <HBB...@t-...>]

Zhong Ren wrote:
> Hi,
> 
> I have a 3D function f(x, y, z) in form of a data file of 4
> columns x, y, z, and f.  The distribution of the function
> value f is symmetrical around 0

Symmetrical --- how?  There are quite a number of symmetries a 3D field 
can have.

Re: [Gnuplot-info] 3D function

[Zhong R. <re...@uc...>]

That means most of the function values are around 0, equal
amount of them are greater than 0 and less than 0.  Less and
less are large positive, and the same amount of them are large
negative.  I said the "function values" are symmetrically
distributed, not x, y, z.  People use red and green nets in 3D
space to represent positive and negative contour surfaces,
respectively.  Hope this clarifies a bit.

Zhong

---- Original message ----
>Date: Wed, 10 Jun 2009 22:34:38 +0200
>From: Hans-Bernhard Bröker <HBB...@t-...>  
>Subject: Re: [Gnuplot-info] 3D function  
>To: re...@uc...
>Cc: gnu...@li...
>
>Zhong Ren wrote:
>> Hi,
>> 
>> I have a 3D function f(x, y, z) in form of a data file of 4
>> columns x, y, z, and f.  The distribution of the function
>> value f is symmetrical around 0
>
>Symmetrical --- how?  There are quite a number of symmetries
a 3D field 
>can have.
>

[Gnuplot-info] contour at base

[Zhong R. <re...@uc...>]

This is one of the demos:

set contour base
splot x**2*y**3, x**3*y**2

It draws two surfaces and contours both at base.  Now, I would
like to put the contours at different z-levels.  Is there a
way to specify them?  I tried to use set xyplane at <z>.  Both
contours went there.  How to separate them at different
levels?  Thanks for any hint.

Zhong

[Gnuplot-info] color string

[Zhong R. <re...@uc...>]

Why can't I do this?  How can I fix it?  Thank you.

Zhong



gnuplot> col(r, g, b) = sprintf('"#%X%X%X"', r, g, b)
gnuplot> print col(255, 23.4, 255)
"#FF17FF"
gnuplot> plot sin(x) w l lc rgb col(255, 23.4, 255)
                                                   ^
         expected a known color name or a string of form "#RRGGBB"

Re: [Gnuplot-info] color string

[Thomas S. <t.s...@fz...>]

gnuplot> col(r, g, b) = sprintf('#%X%X%X', r, g, b)
gnuplot> print col(255, 23.4, 255) 
#FF17FF
gnuplot> plot sin(x) w l lc rgb col(255, 23.4, 255) 

works
'sprintf' returns a string, you don't have to enclose it in quotes.


renzresearch wrote:
> 
> Why can't I do this?  How can I fix it?  Thank you.
> 
> Zhong
> 
> 
> 
> gnuplot> col(r, g, b) = sprintf('"#%X%X%X"', r, g, b)
> gnuplot> print col(255, 23.4, 255)
> "#FF17FF"
> gnuplot> plot sin(x) w l lc rgb col(255, 23.4, 255)
>                                                    ^
>          expected a known color name or a string of form "#RRGGBB"
> 
> 
> ------------------------------------------------------------------------------
> Enter the BlackBerry Developer Challenge  
> This is your chance to win up to $100,000 in prizes! For a limited time, 
> vendors submitting new applications to BlackBerry App World(TM) will have
> the opportunity to enter the BlackBerry Developer Challenge. See full
> prize  
> details at: http://p.sf.net/sfu/Challenge
> _______________________________________________
> Gnuplot-info mailing list
> Gnu...@li...
> https://lists.sourceforge.net/lists/listinfo/gnuplot-info
> 
> 

-- 
View this message in context: http://www.nabble.com/3D-function-tp23965589p24513410.html
Sent from the Gnuplot - User mailing list archive at Nabble.com.