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# Tobin Fricketobin

Last active Sep 4, 2020
Solution to "invert three signals with two not gates" puzzle
View two_nots.py
 # Solution to the following puzzle: # Invert three boolean signals Using only two NOT gates, # and as many AND or OR gates as needed, # # Tobin Fricke 2020-09-03 for x in [True, False]: for y in [True, False]: for z in [True, False]: # If we assume that there is only one solution, then, when searching for the input
Last active May 9, 2017
static const
View static_const.c
 #include #include int main(int argc, char **argv) { const int baz = rand(); // ok! baz = 99; // compile-time error. static int goo = rand(); // compile-time error. goo = 99; // ok.
Created Apr 23, 2014
Integer square root
View exact_sqrt.py
 def exact_sqrt(x): """Calculate the square root of an arbitrarily large integer. The result of exact_sqrt(x) is a tuple (a, r) such that a**2 + r = x, where a is the largest integer such that a**2 <= x, and r is the "remainder". If x is a perfect square, then r will be zero. The algorithm used is the "long-hand square root" algorithm, as described at http://mathforum.org/library/drmath/view/52656.html
Created Nov 21, 2013
Plot the frequency response (Bode plot) of an ideal active twin-T notch
View twinT.m
 % Plot the frequency response of an ideal active twin-T notch, versus % bootstrap feedback gain \alpha. % % Tobin Fricke % 2013-11-21 % Pick the color map (to make the plot pretty) cm = jet(); % Choose the frequency axis
Created May 17, 2013
Notes on PDH waveform
View 3867.txt
 A PDH error signal can be calibrated (into Hz per volt) simply by observing the peak-to-peak amplitude of the PDH signal as the cavity is swept through resonance. Here's the math: An impedance-matched, lossless cavity has amplitude reflectivity of r_c(f) = i f / (i f + pcav) where pcav is the cavity pole, and f is the detuning frequency (i.e. the difference between the frequency of the light and the resonant
Last active Dec 17, 2015
BenQ W600+ Projector EDID/Modelines
Last active Dec 16, 2015
Today I learned
View python.md

This is valid:

M = [1,2,3]
for M[0] in range(0,10):
print M[0]


2013-05-14

The star operator opens tuples and other sequences:

Last active Dec 16, 2015
Solve a magic square variant in Matlab
View fu_puzzle.m
 % Program to solve a sort of magic square, where only the rows and columns % must sum to the magic constant, and not the diagonals. Some elements of % the square are given in advance while others (indicated with 0) are % unknown. % % TF Time-Wasting Project 04-2013 function result = fu_puzzle puzzle = ... [ 1 0 0 0 22
Created Feb 28, 2013
Plot PDH error signal in Gnuplot
View pdh.gnuplot
 f_mod = 35.5e6 pcav = 300e3 i = {0, 1} conj(z) = real(z) - i*imag(z) r_c(f) = i*f / (i*f + pcav) pdh(f) = imag(r_c(f)*conj(r_c(f+f_mod))-conj(r_c(f))*r_c(f-f_mod)) set samples 501
Last active Dec 14, 2015
Experimenting with Numerical Python
View example1.m
 % Matlab code to plot a cavity resonance F = 10; % Finesse f = linspace(-0.5, 1.5, 201); P = 1./(1 + (2/pi) * F^2 * sin(pi*f).^2); plot(f, P); xlabel('free spectral ranges'); ylabel('power buildup');
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