comp.lang.idl-pvwave archive
Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado

Home » Public Forums » archive » Re: how to draw streamline
Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend 
Return to the default flat view Create a new topic Submit Reply
Re: how to draw streamline [message #59309 is a reply to message #59246] Sun, 16 March 2008 22:22 Go to previous message
wfzhao is currently offline  wfzhao
Messages: 11
Registered: March 2008
Junior Member
On 3月14日, 上午4时32分, Chris Torrence <gorth...@gmail.com> wrote:
> On Mar 7, 7:55 am, "Kenneth P. Bowman" <k-bow...@null.edu> wrote:
>
>
>
>
>
>> In article
>> < 92bef8cb-bd54-48b7-b54c-2ff9f4f75...@s8g2000prg.googlegroups .com >,
>
>> wenfang_z...@hotmail.com wrote:
>>> Hi,all
>>> I want to draw the wind streamline map,and I try many methods
>>> described in the forum, but some are wind vectors not the streamline,
>>> which is the serial contour line with arrow on the contour plot.
>
>>> some one ever mentioned that there was a script sample on the web site
>>> http://www.metvis.com.au/idl/
>>> but i can't get access to it.
>
>>> so if there anybody who can load that web site and give a copy of both
>>> the script and the streamline image for me?
>
>>> I will appreciate your help!
>
>>> wenfang
>
>> Here is a sample code to plot 2-D streamlines using VEL.
>
>> By default VEL chooses the initial points randomly, but the
>> source code is available if you want to change that.
>
>> Ken Bowman
>
>> PRO STREAMLINE_DEMO
>
>> n = 50
>> x = FINDGEN(n)/(n-1)
>> y = FINDGEN(n)/(n-1)
>
>> xx = REBIN(x, n, n)
>> yy = REBIN(REFORM(y, 1, n), n, n)
>
>> u = -SIN(!PI*xx)*COS(!PI*yy)
>> v = COS(!PI*xx)*SIN(!PI*yy)
>
>> VEL, u, v, NVECS = 100, NSTEPS = 100, length = 0.5
>
>> END
>
> Following on from Ken's example, you might also try,
>
> iVector, u, v, x, y, /STREAMLINES, STREAMLINE_NSTEPS=25
>
> -Chris
> ITTVIS- 隐藏被引用文字 -
>
> - 显示引用的文字 -

thanks for all response from you.
now I am a litttle comfused, what kind of line can be called as wind
streamline?
what I want is the consecutive line with arrow, something like the
contour plot line with arrow, not the small lines with arrow,I don't
know how to describe it more clear? I have a sample image of wind
streamline ,which is what I want, but how I can put it on the forum so
all of you can have a look and understand what I mean.

I have another question, when drawing a wind streamline, so the speed
of X,Y direction will decide the final appearance of wind streamline?
I menn, if wind is strong, so the result will be the contour plot line
with arrow(long streamline,consecutive), otherwise, the result will be
the discrete lines with arrow(shorted streamline, like what is draw by
the VEL procedure)?

wenfang
[Message index]
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Interactive Image Locations and Values
Next Topic: Re: Writing DICOM-Files

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Sun Oct 12 07:35:59 PDT 2025

Total time taken to generate the page: 0.88066 seconds