Aug 25, 2019
A couple days ago I released Weather Sage 0.1.2.
Weather Sage is a command-line tool and Ruby library to get the
weather forecast and current weather observations for a domestic United
States street address.
It uses the Census Bureau Geocoding API to geocode street
addresses, and the National Weather Service Weather API
to get weather forecasts and current weather observations.
The command-line tool queries the APIs above to obtain the requested
information for the given street address, and then prints the results to
standard output in CSV format.
Here’s an example of using the weather-sage command-line tool to get
the weather forecast for the address 1600 pennsylvania ave nw,
washington dc:
> weather-sage forecast '1600 pennsylvania ave nw washington dc'
address,name,temperature,temperature_unit,wind_speed,wind_direction,short_forecast
1600 pennsylvania ave washington dc,Today,97,F,7 mph,SW,Scattered Showers And Thunderstorms
1600 pennsylvania ave washington dc,Tonight,76,F,2 to 7 mph,SW,Scattered Showers And Thunderstorms then Mostly Cloudy
1600 pennsylvania ave washington dc,Tuesday,94,F,6 mph,E,Slight Chance Rain Showers then Chance Showers And Thunderstorms
1600 pennsylvania ave washington dc,Tuesday Night,75,F,2 to 6 mph,S,Chance Showers And Thunderstorms
1600 pennsylvania ave washington dc,Wednesday,94,F,3 to 9 mph,SW,Chance Showers And Thunderstorms
1600 pennsylvania ave washington dc,Wednesday Night,76,F,5 to 8 mph,SW,Chance Showers And Thunderstorms
...
And here’s an example of using the weather-sage command-line tool to
get the current weather observations from the weather station closest to
the address 1600 pennsylvania ave nw, washington dc:
> weather-sage now '1600 pennsylvania ave washington dc'
address,name,type,value,unit,quality_control
1600 pennsylvania ave washington dc,timestamp,time,2019-08-19T06:52:00+00:00
1600 pennsylvania ave washington dc,textDescription,text,Mostly Cloudy
1600 pennsylvania ave washington dc,temperature,value,26.700000000000045,unit:degC,qc:V
1600 pennsylvania ave washington dc,relativeHumidity,value,81.65039907186703,unit:percent,qc:C
...
You can install Weather Sage via RubyGems like this:
# install weather-sage with rubygems
> gem install weather-sage
Note: This is the initial release, so the API documentation, test
suite, and command-line interface are not yet complete.
Aug 25, 2019
Last week my bag of generic STM32F103C8T6 “Blue Pill” boards
arrived.
So far I’ve flashed Pill Duck and a couple of examples from
Beginning STM32.
Now all I need are some project ideas.
All I’ve come up with so far are another Pocket Jim or another
BME280-based temperature monitor.
Aug 25, 2019
Some stuff I released months ago but never posted:
Aug 25, 2019
A few weeks ago I picked up a 1GB Raspberry Pi 4 Model B and
decided to run some openssl speed benchmarks.
Test systems:
- Raspberry Pi Zero W
- Raspberry Pi 3 Model B
- Raspberry Pi 3 Model B+
- Raspberry Pi 4 Model B
- Linode VM (1 Core)
- Intel i7-8650U (Lenovo X1 Carbon, 6th Gen)
- AMD Ryzen Threadripper 1950X
Test algorithms:
blake2b512blake2s256sha256sha512aes-128-cbcaes-192-cbcaes-256-cbc
Results are available here. The code used to run the tests and
generate the charts is here.
Aug 25, 2019
Last month I wrote a C11 SHA-2 implementation.
Features:
- Self-contained (no external dependencies)
- C11 only (platform-agnostic)
- MIT-licensed
- Includes test vectors (via
make test).
The code is available here.
It includes implementations of the following:
- SHA-224
- SHA-256
- SHA-384
- SHA-512
- HMAC-SHA256
- HMAC-SHA512
This implementation is faster than coreutils, but slower than the
assembly-optimized, processor family-specific OpenSSL SHA-2
implementation:
> time -p ./sha256 ~/Videos/8x*avi > /dev/null
rleal 9.39
user 9.10
sys 0.29
> time -p sha256sum ~/Videos/8x*avi > /dev/null
real 12.04
user 11.73
sys 0.31
> time -p openssl sha256 ~/Videos/8x*avi > /dev/null
real 6.36
user 6.01
sys 0.32
Jun 1, 2019
Range of Battery Electric Vehicles (BEVs) currently available in
the US, according to data from fueleconomy.gov.
Links:
Apr 6, 2019
A recent question from the Something Awful Forums:
Can I run TensorFlow on a Raspberry Pi Zero?
The answer? You can, but it’s a bad idea.
The Raspberry Pi Zero is a single core ARMv6, with no
NEON. Which means it’s slow:
Details
Below are the steps I took to install TensorFlow on a
Raspberry Pi Zero W. Note: you have to use
Virtualenv to install TensorFlow in Raspbian. If you try
to install TensorFlow directly with Pip, the installation will
bomb out with an error.
Raspberry Pi Installation Steps:
# install system pip, numpy dependencies, and virtualenv
sudo apt-get install python3-pip python3-dev libatlas-base-dev virtualenv
# at this point i tried to install tensorflow directly via pip, which does NOT work
# sudo pip3 install --upgrade tensorflow
# created virtualenv environment instead
virtualenv --system-site-packages -p python3 ./venv
# activate virtual environment "venv"
# note: after this command your shell prompt will be prefixed with "(venv) "
source ./venv/bin/activate
# install tensorflow (i also installed keras here, because I use it for other stuff)
# note: this step takes a comically long time (>1 hour)
pip install tensorflow keras
Test Results (Raspberry Pi Zero W):
(venv) pabs@zero:~> time python -c "import tensorflow as tf;
tf.enable_eager_execution();
print(tf.reduce_sum(tf.random_normal([1000, 1000])))"
...
tf.Tensor(1533.9042, shape=(), dtype=float32)
real 0m40.802s
user 0m38.283s
sys 0m1.150s
Test Results (Raspberry Pi 3 Model B+):
(venv) pabs@peach:~> time python -c "import tensorflow as tf;
tf.enable_eager_execution();
print(tf.reduce_sum(tf.random_normal([1000, 1000])))"
...
tf.Tensor(800.62, shape=(), dtype=float32)
real 0m9.408s
user 0m9.227s
sys 0m0.360s
Test Results (AMD ThreadRipper 1950X, 8 core KVM VM, Docker image):
pabs@hive:~> time docker run --rm -it tensorflow/tensorflow:latest-py3 python3 -c \
"import tensorflow as tf; tf.enable_eager_execution();
print(tf.reduce_sum(tf.random_normal([1000, 1000])))"
...
tf.Tensor(-173.73222, shape=(), dtype=float32)
real 0m1.745s
user 0m0.032s
sys 0m0.016s
Apr 6, 2019
Notes on getting KVM, Docker, and TensorFlow to cooperate.
By default, a KVM VM does not have the necessary CPU flags set to
run the TensorFlow Docker image. In particular, the
TensorFlow Docker image is compiled with support
AVX.
The solution:
- Use
virsh capabilities on the host to get a list of host CPU
capabilities, then
- Use
virsh edit to manually add the necessary CPU flags as
<feature> tags under the <cpu> tag.
I elected to add all of the SIMD capabilities, including FP16.
For an AMD Threadripper 1950X, the resulting <cpu> tag
looks like this:
<cpu mode='host-model'>
<model fallback='allow'/>
<feature policy='require' name='sse4.1'/>
<feature policy='require' name='sse4.2'/>
<feature policy='require' name='avx'/>
<feature policy='require' name='f16c'/>
<feature policy='require' name='avx2'/>
<feature policy='require' name='ssse3'/>
</cpu>
Test run:
pabs@hive:~> time docker run --rm -it tensorflow/tensorflow:latest-py3 \
python3 -c "import tensorflow as tf; tf.enable_eager_execution();
print(tf.reduce_sum(tf.random_normal([1000, 1000])))"
2019-04-06 12:25:16.576095: I tensorflow/core/platform/cpu_feature_guard.cc:141]
Your CPU supports instructions that this TensorFlow binary was not compiled to
use: AVX2 FMA
2019-04-06 12:25:16.627588: I tensorflow/core/platform/profile_utils/cpu_utils.c
c:94] CPU Frequency: 3393620000 Hz
2019-04-06 12:25:16.629909: I tensorflow/compiler/xla/service/service.cc:150] XL
A service 0x395bf00 executing computations on platform Host. Devices:
2019-04-06 12:25:16.629968: I tensorflow/compiler/xla/service/service.cc:158]
StreamExecutor device (0): <undefined>, <undefined>
tf.Tensor(-95.5094, shape=(), dtype=float32)
real 0m1.780s
user 0m0.024s
sys 0m0.012s
Apr 4, 2019
This weekend I put together a simple password strength tester. You can
try it out here.
Features:
- Simple interface.
- Open source (MIT licensed).
- Easy to inspect. The interface code is contained in a single,
<300 line JavaScript file.
- Self-contained. No external connections for assets, social media
sites, analytics, etc.
- Can be run offline (no internet connection) or locally (by downloading
an archive of the the Git repository).
Built with:
- zxcvbn: JavaScript password strength estimator.
- Bulma: Open source CSS framework.
- font-awesome: Open source font icons.
Links:
Apr 3, 2019
Took delivery on my Tesla Model 3 (LR AWD) one week ago today.
So far it’s great!
I’ve been taking notes on everything, and I will share them eventually.
