Mathematics

LaTeX

Although not strictly used for mathematics, LaTeX it is an extremely useful tool for typesetting. It is a what you see is what you mean editor, in that formatting is done using LaTeX's own unique markup language. LaTeX allows one to do a number of typesetting tasks automatically, that can be major headaches using a traditional word processor. Finally, LaTeX allows for the beautiful display of mathematics. I will not cover usage here, but you can find a lot of information at LaTeX's homepage.

cd /usr/ports/print/teTeX
make install clean

This will take a while, but will provide us with a LaTeX distribution to work with. If you have a .tex file that you want to convert into .pdf, use the following command:

texi2pdf -c file.tex

The 'c' flag will clean all of the extra files that are created to process the .tex file.

If you want to add a new style to your distribution, there are a few steps you must follow. First, create a directory for it (corresponding to the style's name 'anonchap' for this example) and move the style into it (these commands are written from the directory containing the style):

mkdir /usr/local/share/texmf-dist/tex/latex/anonchap/
mv anonchap.sty /usr/local/share/texmf-dist/tex/latex/anonchap/

Now we just need to update the distribution:

texhash

Good luck with the wonderful system that is LaTeX!

PyX

In the world of unix-like operating systems, PyX is by far the most useful and powerful plotting software I have encountered. PyX is really just a graphics package for python, so when working with PyX one has access to all of the power (and headaches) of python. One excellent feature of PyX is that it provides one with the wonderful typesetting capabilities of LaTeX, which allows one to generate wonderful looking images.

cd /usr/ports/graphics/py-PyX
make install clean

The easiest way to use PyX is to create a python file, say 'file.py,' and use the python compiler to process the file.

python file.py

Although PyX provides quite a learning curve to using, I will provide a sample file `derivative_velocity_car.py' here to give some indication of what it is capable of.

from pyx import *
from pyx.graph import axis

def f(x):
     if 0 <= x < 1: return x
     elif 1 < x <= 2: return 1

def h(x):
     if 2 < x < 4: return -1/(x-1)**2
     elif 4 <= x: return -16/(9*x**2)

g = graph.graphxy(width=8,
     x=axis.linear(min=0, max=6, title="$t$"),
     y=axis.linear(min=-2, max=2, title="$v(t)$"))

g.plot(graph.data.function("y(x)=f(x)", context=locals(), points=500))
g.plot(graph.data.function("y(x)=h(x)", context=locals(), points=500),[graph.style.line([style.linestyle.solid])])

g.finish()

g.stroke(g.ygridpath(0), [style.linestyle.dashed,style.linewidth.Thin])
g.stroke(g.xgridpath(0), [style.linestyle.dashed,style.linewidth.Thin])

u1,v1 = g.pos(2,1)
u2,v2 = g.pos(2,-1)

g.stroke(path.circle(u1,v1,0.07),[deco.filled([color.rgb.white]) ])
g.stroke(path.circle(u2,v2,0.07),[deco.filled([color.rgb.white]) ])

g.writeEPSfile("derivatives_car_velocity")

The first two lines relate to loading PyX for usage with python. Next we define two functions, in order to plot a piecewise function without having the pieces connected. Afterwards we setup the plot, and use g.plot to actually graph our functions. By default PyX will use a second linestyle for the second function, but because these are both the same function we want them both to be solid. We use g.finish to finish up the plot, and afterwards we add the x and y-axes. Finally, as a finishing touch we add the little circles to show where the function is and isn't defined at points. Using g.pos we can refer to coordinates that are already a part of the plot, and then we simply draw some little circles there. In order to run the file we simply issue

python derivatives_car_velocity.py

and python will write a derivative_car_velocity.eps for us. Next we convert to .pdf using

epstopdf derivatives_car_velocity.eps

The resulting image is given below.

Inkscape

Inkscape is a vector graphics editor, in contrast to a raster image editor, like GIMP. What this means is that drawings are made using mathematical objects (vectors) rather than pixels. This greatly reduces the size of images, as well as adding resizability without any loss in quality. For generating somewhat complicated images (other than plots), inkscape serves as a very nice alternative to PyX. Also, inkscape allows for the usage of LaTeX-text, which is a must.

cd /usr/ports/graphics/inkscape
make install clean

The above command will install inkscape, but we need to do a little bit more work for LaTeX support.

cd /usr/ports/graphics/pstoedit
make install clean
cd /usr/ports/devel/py-lxml
make install clean

These two ports will give us the prerequisites to use the textext package, found here. Go ahead down to the files section of that page and download the latest .tar.gz, which in this case was textext-0.4.2.tar.gz. As root, go ahead and move the tarball and extract it as follows

cd /usr/local/share/inkscape/extensions
mv textext-0.4.2.tar.gz .
tar -xf textext-0.4.2.tar.gz

Now when we launch inkscape we will have the option to insert LaTeX text into the image. Launch inkscape with

inkscape &

In order to use LaTeX text, choose 'Tex Text' from the Effects menu.

Back to our FreeBSD Guide Home