Category Archives: Python

3D Printing a dome house

Posted on June 7, 2016 by janpenguin

(1/9/2021) I caught up in life and stopped programming some years ago. I’m uncertain when will I finish the project. I have requested few times about the source code. Here is the link of github repository. https://github.com/ghpenguin/workshop (old) I’ve … Continue reading →

Posted in GNU/Linux, Python, Science and technologies | Tagged engineering, geodesic dome, Geodome, house project, python 3.x | Leave a comment

Extracting numbers using regular expression

Posted on May 31, 2016 by janpenguin

It took hours to understand how the regular expression works. I briefly explains the symbols in the codes. . any single character ? zero or one of the previous character + one or more of the previous character * zero … Continue reading →

Posted in Python | Tagged numbers, python, re, regular expression | Leave a comment

Build IPython for Python 3.x

Posted on December 25, 2015 by janpenguin

I use IPython as SymPy interface which serves as command-line CAS (Computer Algebra System) application. It’s one of critical software I depend on whenever I study mathematics. I decided to uprade IPython for Python 3.x because I felt making Python … Continue reading →

Posted in GNU/Linux, Python | Tagged CAS, Devuan, ipython3, matplotlib, module installation, numpy, pip3, python-pip3, python3.4, SymPy | 1 Comment

Starting ipython for interactive sympy

Posted on December 24, 2015 by janpenguin

$ ipython –pylab Python 2.7.10+ (default, Oct 10 2015, 09:11:24) Type “copyright”, “credits” or “license” for more information. IPython 2.3.0 — An enhanced Interactive Python. ? -> Introduction and overview of IPython’s features. %quickref -> Quick reference. help -> Python’s … Continue reading →

Posted in GNU/Linux, Python | Tagged graph, Ipython, plot, SymPy | Leave a comment

ztouch – create empty files

Posted on July 6, 2014 by janpenguin

Out of necessity I built a simple program that create many empty files. I put few examples how to use it in the code. Below command create exactly 1,000 empty files which mimic Nikon D200’s image files. The first file … Continue reading →

Posted in GNU/Linux, Python | Tagged command line utility, create empty files, Debian Wheezy, programming, python, touch, ztouch | 1 Comment

sympy – find equations for the lines that are tagent and normal to the curve at (1, 2).

Posted on February 3, 2014 by janpenguin

Chapter 2 Practice Exercises, p183

Posted in Python | Tagged Calculus, mathematics, normal line, python, SymPy, tangent line | Leave a comment

sympy – changing graph color of plot()

Posted on February 1, 2014 by janpenguin

plot() handles color names for RGB color codes. SymPy document doesn’t explain it clearly or sample codes don’t exit. Here is another example.

Posted in Python | Tagged Calculus, color name, mathmatics, plot, python, rgb color, SymPy | 1 Comment

sympy – an example of implicit differentiation

Posted on January 31, 2014 by janpenguin

Posted in Python | Tagged Calculus, implicit differentiation, python, SymPy | Leave a comment

sympy – sawtooth function

Posted on January 29, 2014 by janpenguin

Calculus and Analytic Geometry, George B. Thomas and Ross L. Finney Exercises 2.5 81, p163 s = 0.78540 – 0.63662*cos(2*t) – 0.07074*cos(6*t) – 0.02546*cos(10*t) – \ 0.01299*cos(14*t) plot(s, (t, -pi, pi)) dsdt = 1.27324*sin(2*t) + 0.42444*sin(6*t) + 0.2546*sin(10*t) + 0.18186*sin(14*t) … Continue reading →

Posted in Python, Science and technologies | Tagged Calculus, cos(x), derivative, mathematics, python, sawtooth function, sin(x), step function, SymPy | Leave a comment

sympy – appling the chain rule manually to find derivative of a function.

Posted on January 28, 2014 by janpenguin

I spent few hours to figure out how to apply the chain rule manually to find derivative of a function due to poor documentation of SymPy. I’m not that smart guy.

Posted in Python | Tagged Calculus, chain rule, derivative, mathematics, SymPy | Leave a comment