January 2019 – The Libre Hacker

LibreCMC v1.4.5 Builds

January 28, 2019 thequietlearnerLeave a comment

A bit late, but the builds are available here:

ftp://lavender.qlfiles.net/librecmc/v1.4.5/

These builds are pre-compiled with a lot of extra networking tools, not included by default in the default builds. Here are packages & options I enabled:

Netcat server options and extensions
Busybox whois
Busybox arp and arping
Busybox ip neighbor
Busybox telnet (client)
Busybox tftp client
Busybox iostat
BB Lsof
BB watch
BB flock
dnsmasq-dhcpv6 (instead of dnsmasq)
Dropbear EEC support
Tinyscheme with embedded and extensions
luci-ssl-openssl
luci-app-openvpn
luci-app-wifischedule
luci-theme-material
lftp
wget
ebtables & ebtables-utils
ncat-ssl
nmap-ssl
nping
nstat
ss
tc
lldpd
openvpn-openssl
wavemon
6in4
arp-scan
darkstat
iftop
iperf3
tcpdump
nano
zile
dropbearconvert

Here are the sums:

fb1b26ad9cbd2599143245d4fd80d9356890dd106b3a0049e222ca5c22b96770  generic/librecmc-ar71xx-generic-gl-ar150-squashfs-sysupgrade.bin
 c22995acadd8a4713873c3e57cc9ed7c72cd49e83c3ee05e7d9878bf852f9096  generic/librecmc-ar71xx-generic-gl-ar300m-squashfs-sysupgrade.bin
 fb1b26ad9cbd2599143245d4fd80d9356890dd106b3a0049e222ca5c22b96770  generic/librecmc-ar71xx-generic-tpe-r1100-squashfs-sysupgrade.bin
745d8ca091dc3505348e8dc7ac5519ae65094370d0587f2065f4b023689e00db  nand/librecmc-ar71xx-nand-gl-ar300m-ubi-factory.img

Perfect Shapes From Circles

January 25, 2019 thequietlearnerLeave a comment

Here is a diagram illustrating how perfect triangles and perfect hexagons may be constructed from circles:

System Information Scripts for Gnu/Linux

January 25, 2019 thequietlearner1 Comment

Somebody tipped me off to two useful software tools which display detailed system information. This is especially helpful if you are making a tech support forum post and want to provide detailed information about your system. The first is inxi:

First, you need to run the commands sudo update-usbidsand sudo update-pciids, then inxi -Fxz to get the interesting information.

The other command is neofetch which gives a condensed description of your desktop environment and some other basic system information:

Neither of these programs are likely to be installed by default on a system, but they are likely to be in your distro’s package repository.

More complex number patterns

January 25, 2019January 25, 2019 thequietlearner2 Comments

An interesting question was what would happen if I used other simple ratios other than a fraction of unity. I added this function to make this easier:

(define (coscompplot ang m n)
  (complexplot
   (lambda (n) (* (cos (* n ang)) (expt (exp 0+1i) n)))
   0 200))

screenshot from 2019-01-25 06-52-05

Quite interesting. Well, now off to my day job!

Beautiful Complex Number Traces

January 24, 2019 thequietlearner1 Comment

I got a lot of work done on the bookkeeping, but I couldn’t go to bed without playing with the complex number plots some more. I found an a way to produce some attractive plots. First, I needed this additional function, to make experimentation easier:

(define (complexplot f m n)
  (plot
   (lines
    (map (lambda (n)
           (complex2vec (f n)))
         (range m n)))))

The idea I came across was taking the standard unit circle rotation, and multiplying that by samples of the cosine wave:

screenshot from 2019-01-24 23-31-35

TA DA!

If I change the “sampling rate” to various fractions of Pi, I get other interesting geometry. Here is Pi/4:

Screenshot from 2019-01-24 23-32-22.png And Pi/7:

screenshot from 2019-01-24 23-32-12