Subversion Repositories wimsdev

!goto $wims_read_parm

:def

title=Plot implicit curve

synonyme=implicit plot, implicit curve plot, implicit curve 2D, plane implicit curve plot, plot plane implicit curve

input=equation

!exit

:proc

formula=!item 1 of $formula

fml=!mathsubst X=x in $fml

fml=!mathsubst Y=y in $fml

eq==

!if $eq isin $formula

 f=!translate internal = to , in $formula

 !distribute items $f into f1,f2

 !if $f2=$empty or $f1=$empty

  error=bad_formula

  !exit

 !endif

 fml=$f1 - ($f2)

!else

 fml=$formula

!endif

result=$fml

x1=$[$xrange1]

x2=$[$xrange2]

y1=$[$yrange1]

y2=$[$yrange2]

s1=$[$picturesize1]

s2=$[$picturesize2]

!distribute item -2,2,-2,2,260,260 into dx1,dx2,dy1,dy2,ds1,ds2

!for r in x1,x2,y1,y2,s1,s2

 !if NaN isin $($r)

  $r=

 !endif

 !default $r=$(d$r)

!next r

insdraw_size=$s1,$s2

!exit

:output

Plane implicit curve defined by

!htmlmath $formula

 :

<p><center>

!insdraw xrange $x1,$x2\

yrange $y1,$y2\

arrow $x1,0,$x2,0,10,grey\

arrow 0,$y1,0,$y2,10,grey\

levelcurve red,$fml,0

</center>

!exit