JRSETI Wiki

android_misc

Anonymous (anonymous@undisclosed.example.com) — 2020-03-10T03:29:41+00:00

Android Miscellaneous Handler A Handler allows you to send and process Message and Runnable objects associated with a thread's MessageQueue. private class DataSentRunnable implements Runnable { private RPStream stream; public DataSentRunnable(RPStream stream) { this.stream = stream; } public void run() { parent.onDataSent(stream); } } Handler handle = new Handler(); this.handler.post(cr); (or postDelayed())

android_study_2

Anonymous (anonymous@undisclosed.example.com) — 2020-03-10T03:06:59+00:00

Android Study 2 Things I have done in my apps. NFC * Configure the NFC: private void configureNfc(){ mNfcAdapter = NfcAdapter.getDefaultAdapter(this); mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); Log.v(LOG_TAG, "NFC enabled = " + mNfcAdapter.isEnabled()); IntentFilter intnfcv = new IntentFilter( NfcAdapter.ACTION_TECH_DISCOVERED); …

android_study

Anonymous (anonymous@undisclosed.example.com) — 2020-03-10T01:58:26+00:00

Android Study Background Processing Guide to Background Processing Doze Doze Alarms to not fire in Doze mode. Foreground Services Effective Foreground Services Background Location Background Location Limits Saving Data * Shared Preferences * SQL IME KEyboard Input Starting from Android 1.5, the Android platform offers an Input Method Framework (IMF).

android

Anonymous (anonymous@undisclosed.example.com) — 2021-02-04T22:22:24+00:00

Android Android Studio Ignored Files * build (and build directory if there are multiple modules in a project) * .idea * *.iml * local.properties * .DS_Store * .gradle * .cxx Pull APK from device Get the list of installed packages to determine what to pull:

data_structures

Anonymous (anonymous@undisclosed.example.com) — 2020-01-12T16:43:57+00:00

Data Structures and Algorithms * Stacks, Queues, Dequeues * Linked Lists * Trees * Sorts * Huffman Encoding * LRU * Graphs

data_viz_class

Anonymous (anonymous@undisclosed.example.com) — 2020-09-12T17:22:10+00:00

Data Visualization Class Module 1 - Excel * Week 1 * Week 2

data_viz_week_1

Anonymous (anonymous@undisclosed.example.com) — 2020-09-13T20:29:04+00:00

Excel Week 1 Recommended Class Required Class Module Lesson * Excel zooming * Excel Worksheet * Column Headers, Row Indexes * New Worksheet * Cmd-right arrow takes you to the last column * Timestamp Converter! * Formatting columns type

embedded

Anonymous (anonymous@undisclosed.example.com) — 2020-04-05T18:57:58+00:00

Embedded Overview Overview of embedded system development. Key Parameters * Memory * Storage * Power * Processing power Tips On ARM Processors: * Unordered List ItemGenerally local variables are allocated in registers. However if we take the address of a local variable, compiler will not allocate the variable to register.

graphs

Anonymous (anonymous@undisclosed.example.com) — 2020-01-13T00:22:01+00:00

Graphs * Nodes, Edges * No root node like trees * Edges can contain data, like strength of conection, etc. * Edges can have a direction, “Directed Edge” * “Undirected Graph”, Edges with no direction * Graphs can loop back to the start, unlike Trees

huffman_encoding

Anonymous (anonymous@undisclosed.example.com) — 2020-01-12T04:59:38+00:00

Huffman Encoding Huffman Coding Wikipedia From Data Algo Class import sys import queue class Node: def __init__(self, ch, freq, left, right): self.left = left self.right = right self.ch = ch self.freq = freq class Tree: def __init__(self, root = None): self.root = root def get_root(self): return self.root def __str__(self): visit_order = list() def traverse(node): if node: #…

interviews

Anonymous (anonymous@undisclosed.example.com) — 2020-04-05T18:30:01+00:00

Scheduled Interviews Google * Technical - 2 Python coding and algorithms (45 min) * Technical - 1 Embedded system design (60 min) * Technical - Mix of general python coding/embedded knowledge (45 minutes) * Non technical - Technical leadership & Googleyness (45 minutes)

ios_stuff

Anonymous (anonymous@undisclosed.example.com) — 2021-03-03T21:49:26+00:00

IOS Stuff Getting the IPA file The Veri app required me to look through the app contents to see if I could determine anything. Used the “App Configurator 2” available from the app store. I had to use the new MAC, my 17 inch has too old an OS

java_primer

Anonymous (anonymous@undisclosed.example.com) — 2020-11-19T17:19:37+00:00

Java Primer Maps Hash Maps HashMap hmap = new HashMap(); * O(l) lookup and insertion. * Can have one null key and multiple null values TreeMaps * are 0(logn) lookup and insertion. * But, keys are ordered! * No null keys

leadership

Anonymous (anonymous@undisclosed.example.com) — 2020-11-18T16:26:04+00:00

Leadership What they look for: * Define clear goals * Develop a plan * Delegate Tasks * Manage Progress * Maintain Focus Situations To Use As Examples * Adam @ Highwire * Jane and Flora, legacy employee * Dealing with Gerry not being responsive

libwebsockets

Anonymous (anonymous@undisclosed.example.com) — 2021-05-13T17:47:52+00:00

Installing install openssl install cmake (use brew) mkdir build cd build cmake .. -DLWS_ROLE_WS=1 -DOPENSSL_ROOT_DIR=/usr/local/opt/openssl/ -DOPENSSL_CRYPTO_LIBRARY=/usr/local/opt/openssl/lib/libcrypto.a make make install cd include sudo cp -r /usr/local/opt/openssl/include/openssl /Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/include/ sudo cp libwebsockets.h /Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/include/ sudo cp lws_config.h /Library/Developer/CommandLineTo…

linked_lists

Anonymous (anonymous@undisclosed.example.com) — 2020-01-12T05:11:33+00:00

Linked List class Node: def __init__(self, value): self.value = value self.next = None def __repr__(self): return str(self.value) class LinkedList: def __init__(self): self.head = None

lru

Anonymous (anonymous@undisclosed.example.com) — 2020-01-12T05:20:17+00:00

Least Recently Used Cache LRU Good explanation at LRU Cache Implementation From Data Algo class: """ Implement an LRU cache The trick here is to use an OrderdDict. When adding a value delete it from the dict if it exists, then put it on so it is at the end of the dict. If over capacity then remove the first value and add the new value, thus removing the least used. """ from collections import OrderedDict class LRU_Cache(object): def __init__(self, capacity): self.capacity =…

outco

Anonymous (anonymous@undisclosed.example.com) — 2020-05-03T15:59:30+00:00

Outco Precourse Outline

python_commenting

Anonymous (anonymous@undisclosed.example.com) — 2019-12-11T23:33:20+00:00

Python Commenting Good example: Module Example, at top #!/usr/bin/env python3 # -*- coding: utf-8 -*- """Determine flux densities of sources based on Perley and Butler, 2016. Using the method defined in Perley and Butler, 2016: https://arxiv.org/pdf/1609.05940.pdf calculate the flux densities of various sources from 1 to 10GHz and optionally produce a graph that is automatically displayed in a browser. Author: Jo…

python_formatting

Anonymous (anonymous@undisclosed.example.com) — 2019-12-11T22:31:47+00:00

Python Formatting * autopep8 --in-place --aggressive --aggressive * yaph -i * pylint To disable one file from yapf formatting, place this at the end of the line in code: #yapf: disable

python_setup

Anonymous (anonymous@undisclosed.example.com) — 2019-12-28T19:19:19+00:00

Python Project Setup How to create a project suitable for PyPI * How to create a command line version of your python script DONT USE python setup.py install, use “pip install .”. Otherwise console scripts do not work. You need a MANIFEST.in file!! Manifest.in needs to include requirements.txt for it to get added into the distribution. Add this line:

python_testing

Anonymous (anonymous@undisclosed.example.com) — 2019-12-21T18:52:22+00:00

Python Testing python setup.py test Example flux_densities/tests/test.py: from unittest import TestCase import flux_densities as fd class TestFluxDensities(TestCase): def test_souurce_list(self): source_list = fd.get_sources() assert(len(source_list) == 20)

python_tips

Anonymous (anonymous@undisclosed.example.com) — 2019-12-28T18:39:39+00:00

Python Tips From the book Serious Python (page 11-12) Pep8, pyflakes, use “flake8” which compibes the two. (page 7) Project structure. (page 25) “pip install -e .” (page 34) Documentation with Sphinx.

python_tricks

Anonymous (anonymous@undisclosed.example.com) — 2019-12-23T18:11:59+00:00

Python Tricks Reversing an Array [::-1]

python_virtual_env

Anonymous (anonymous@undisclosed.example.com) — 2019-12-18T15:57:37+00:00

Python Virtual Environment A good primer is at How I set mine up * Create a new directory and cd to it * python3 -m venv env * source env/bin/activate * (to get out of this environment) “deactivate” * git clone into this directory More stuff to install

python

Anonymous (anonymous@undisclosed.example.com) — 2020-07-16T16:22:57+00:00

Python Help and Hints * Python Virtual Environment * Python Project Setup * Python Testing * Python Formatting, checking code syntax * Python TRICKS! * Python tips * Google Python Style Guide * Commenting * Rst and Sphinx formatting What to put at the top (I always forget!) #!/usr/bin/env python3 # -*- coding: utf-8 -*- import sys import os print("HERE") Code Complexity Cheat-Sheet!

sidebar

Anonymous (anonymous@undisclosed.example.com) — 2023-10-28T19:22:21+00:00

____ Menu ____ * Python * Linux * Android * Web Stuff * Data Structures and Algorithms * Android Study * Android Study 2 * Android Miscellaneous * Java Primer * Embedded * Study 1 * Study 2 * Data Visualization Class * IOS Stuff * libwebsockets

stacks_queues

Anonymous (anonymous@undisclosed.example.com) — 2020-01-14T02:16:36+00:00

Stacks, Queues, Dequeues heapqueue heapq.heappush(heap, item) Push the value item onto the heap, maintaining the heap invariant. heapq.heappop(heap) Pop and return the smallest item from the heap, maintaining the heap invariant. If the heap is empty, IndexError is raised. To access the smallest item without popping it, use heap[0]. heapq.heappushpop(heap, item) Push item on the heap, then pop and return the smallest item from the heap. The com…

start

Anonymous (anonymous@undisclosed.example.com) — 2020-05-03T15:42:15+00:00

Welcome to my WiKi This is a general mish-mash of notes for my computer programming life. * Quasilinear - O(nlogn), such as for sorts. * Binary search - O(logn) Select this to edit the left menu sidebar - if you have permissions.

study_1

Anonymous (anonymous@undisclosed.example.com) — 2020-06-15T17:03:36+00:00

713. Subarray Product Less Than K Leetcode 713 562. Longest Line of Consecutive One in Matrix Leetcode 562 222. Count Complete Tree Nodes Leetcode 222 207. Course Schedule (Topological Sort) Leetcode 222 15. 3Sum Leetcode 15 16. 3Sum Closest Leetcode 16 17. Letter Combinations of a Phone Number Leetcode 17 27. Word Ladder

study_2

Anonymous (anonymous@undisclosed.example.com) — 2020-11-03T21:32:00+00:00

One hour interview Video Binary Heaps Good Binary Heap Tutorial enqueue or dequeue items in O(logn) Priority Queues use a min heap or max heap. In Java use the Comparator: import java.util.*; ... PriorityQueue pq = new PriorityQueue(5, new StudentComparator()); ... Class StudentComparator implements Comparator{ // Overriding compare()method of Comparator …

trees

Anonymous (anonymous@undisclosed.example.com) — 2020-01-12T05:02:39+00:00

Trees class Node: def __init__(self, ch, freq, left, right): self.left = left self.right = right # Whatever values you want to store self.ch = ch self.freq = freq class Tree: def __init__(self, root = None): self.root = root def get_root(self): return self.root def __str__(self):

web_stuff

Anonymous (anonymous@undisclosed.example.com) — 2023-10-28T19:21:21+00:00

Web Stuff SSL Certificate * Follow these instructions LetsEncrypt * Installing with nginx