KnotPlot script for InfinityCabled

This page gives an example of a KnotPlot script that can be used to generate an Encapsulated PostScript (EPS) file. A bitmap preview of the EPS file is shown below. The EPS file is vector graphics, and is generally higher quality than the preview. To play with the KnotPlot script, you will need to download a copy of KnotPlot.

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Following is a detailed description on how the KnotPlot script was used to generate the files on this page. Example shown is for letter size paper. See the note (right) about printing to A4 paper. If you're only generating an EPS file for inclusion in another document, then you don't need to worry about setting the pagesize.

Run KnotPlot in non-graphics mode to generate the EPS file.

knotplot -nog < InfinityCabled.kps

One could instead run KnotPlot in graphics mode and enter the following command into the KnotPlot Command Window

<InfinityCabled.kps

We now have the file InfinityCabled.eps which could be printed directly on a PostScript printer. For printing to a non-PostScript printer, generate a PDF file InfinityCabled.pdf from the EPS file InfinityCabled.eps using Ghostscript.

# Note: enter the following three lines on one command line
gs -dCompatibilityLevel=1.3 -q -dNOPAUSE -dBATCH
   -sPAPERSIZE=letter -sDEVICE=pdfwrite
   -sOutputFile=InfinityCabled.pdf -c .setpdfwrite -f InfinityCabled.eps

The remainder of this example shows how the preview image seen above was created. This is useful for including an image on a web page or in a presentation. Printing the EPS or PDF file will give much higher quality than printing the preview image. These files, InfinityCabled.eps and InfinityCabled.pdf, as well as their counterparts for A4 paper, InfinityCabled_a4.eps and InfinityCabled_a4.pdf, can be downloaded using the links in the right hand panel on this page.

# run Ghostscript to generate a temporary PPM file
# Note: enter the following two lines on one command line
gs -q -dNOPAUSE -dBATCH -sPAPERSIZE=letter -sDEVICE=ppmraw
   -sOutputFile=InfinityCabled.ppm -r200 -f InfinityCabled.eps
 
# scale it down using ImageMagick convert command
convert -resize 600x InfinityCabled.ppm InfinityCabledS.ppm
 
# reduce the number of distinct colours and create the gif
convert -colors 32 InfinityCabledS.ppm InfinityCabled.gif
 
# delete temporary files
/bin/rm InfinityCabled.ppm InfinityCabledS.ppm

KnotPlot script that generated the Encapsulated PostScript (EPS) file:

% KnotPlot script: InfinityCabled.kps
% Sat 09 Mar 2019 01:47:55 UTC

alloc 5555
cyl-rad=.4
psmode=41
pserase=2
psoption bbox small

load infinity
scale 1.4 1 1
double
Draw=f
refine 33
warp install
d-torus=.6
cyl-rad=.2

torus 4 43 876
warp along 
length
save |infcab1

torus 4 43 876
warp bbconf
warp along 
length
save |infcab2

torus 4 43 876
alternate
refine 2
warp bbconf

Draw=t

warp along
length

trans 0 -8 0
load comb |infcab2
trans 0 -8 0
load comb |infcab1

psscale=29
centre

psout InfinityCabled

% End of KnotPlot script

This script generates a EPS file (download below) suitable for printing on letter size paper. For printing on A4 size paper, use the command psop pagesize a4 prior to the psout command.

Download a high quality PDF or EPS file (for either letter or A4 size paper):

• InfinityCabled.pdf (110 kbytes)
• InfinityCabled_a4.pdf (109 kbytes)
• InfinityCabled.eps (207 kbytes)
• InfinityCabled_a4.eps (208 kbytes)

The PDF files and the preview image seen on this page were generated from the EPS files using Ghostscript (details in left panel on this page).