Subversion Repositories wimsdev

!set p_=!word 1 of $wims_read_parm
!bound p_ within none,header,source,html default none
!goto $p_
:none
!exit
:header
!set m_subject=Level curves
!set m_date=20020515
!set m_time=11:01:44
!set m_from=Gang XIAO
!set m_sender_ip=127.0.0.1
!set m_sender_id=
!set m_sender_class=
!set m_email=xiao@unice.fr
!set m_to=
!set m_prec=O200205/1
!set m_exists=yes
!exit
:source
<pre>
WIMS now incorporates a 2D level curve plotting engine. It can be
accessed in messages, documents and OEF exercises via the &lt;tt>\\draw&lt;/tt> command, and all the usual facilities (animation, width, color) apply to the level curves. For example, you can go to the unformatted view of this message for the command syntax of the following animation.
&lt;p>&lt;center>
\draw{250,250}{
animate 20,0.3,0
v=1.3
xrange -v,v
yrange -v,v
arrow -v,0,v,0,10,grey
arrow 0,-v,0,v,10,grey
linewidth 2
levelcurve green,x^4+y^4+(cos(s*pi)*x-sin(s*pi)*y)*(sin(s*pi)*x+cos(s*pi)*y),0,-0.06,0.2,0.6,1
}
&lt;/center>&lt;p>
In WIMS language, there is also a command &lt;tt>!levelpoints&lt;/tt> that outputs the list of coordinates of the points in the level curve. But this can only be used with simple curves and a very small number of levels, otherwise the huge amount of data will overflow the string length limit, and generate errors.</pre>
!exit
:html
WIMS now incorporates a 2D level curve plotting engine. It can be
accessed in messages, documents and OEF exercises via the <tt>\draw</tt> command, and all the usual facilities (animation, width, color) apply to the level curves. For example, you can go to the unformatted view of this message for the command syntax of the following animation.
<p><center>

!read primitives.phtml 1, draw, 250,250, animate 20,0.3,0       v=1.3   xrange -v,v     yrange -v,v     arrow -v,0,v,0,10,grey  arrow 0,-v,0,v,10,grey  linewidth 2     levelcurve green,x^4+y^4+(cos(s*pi)*x-sin(s*pi)*y)*(sin(s*pi)*x+cos(s*pi)*y),0,-0.06,0.2,0.6,1   

</center><p>
In WIMS language, there is also a command <tt>&#33;levelpoints</tt> that outputs the list of coordinates of the points in the level curve. But this can only be used with simple curves and a very small number of levels, otherwise the huge amount of data will overflow the string length limit, and generate errors.