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Friday, August 17, 2018

Password protect and zip compress files on Mac

The following step is only recommended for developers who have experience working in the command line. This is the build-in zip compress and password protect function in Mac, so it is free.

It's very difficult if not impossible to undo command line changes. So please, only use this option if you are familiar with command line scripts.

Data Science beyond the basics

Exploratory Data Analysis

  • Histogram plotting, input is a list of distributions we want to plot,  specify bins, can also weigh each sample differently, it doesn't have to be count 1. hist function can return values.  How many items in each bin, and the plot. 
  • It is also important to do feature extraction, simply the data, reduce computational cost, dimensionality reduction before feeding data into a machine learning algorithm. Algorithms will run faster, more efficiently, use less memory space, and even perform better, in some cases. 
  • Anomaly detection, outlier detection to handle or remove outliers and abnormality in the data to help the model generalize better and be a more accurate representation. 

Machine Learning

Machine Learning is emerging as a popular field of data science. It has predictive power, employs applied statistics and pattern recognition technologies.

Machine learning is taking data mining to the next level.

Major machine learning tasks include classification, regression and clustering.

Questions that Business Analysts and Decision Makers are Interested In

  • Who are the best customers? aka Who are the customers with the best Customer Life Value
  • Causal relationship: 
    • Results of recent experiments (More prevalent in Startup Culture)
    • Hypothesis if one segmentation is actually different from another
    • Is the result significant or is it random chance
    • Please note that causal relationship determination requires controlled studies to control for extraneous variables. In many industries, such as biotech, statistical significance is a must, a prerequisite for next step analysis or more business investments. 
    • Demo graphics of customers. Summary statistics, customer segmentation and more. 
    • How to measure profitability and other Key Performance Indicators (KPI)

Statistical Hypothesis Testing

Python for Data Science

  • Use conda command similar to pip for installing and launching packages
  • Anaconda comes with a wonderful Python IDE called Spyder

Scientific Computing using Scipy

  • Scipy.integral.quad using the quad method to compute integral function to compute, lower bound, first bound, a tuple, returns an approximation of the result and how much error

Sunday, August 5, 2018

Lifehack Productivity Tips for Business Bay Area Professionals No.101

General Productivity
  • Did you know that having a daily routine improves efficiency and productivity? Mark Zuckerberg of Facebook famously wear the same grey shirt and hoodie on a daily basis to simplify wardrobe choices and save minutes each day. 
  • Automate everything: use API connectors to connect applications such as Gmail, Shopify and Trello without coding: Zapier, IFTTT, Do Button
  • Fix your iphone, your glasses your gadgets DIY style https://www.ifixit.com/
  • Tool for Youtube Creators SoundCloud audio editing https://blog.soundcloud.com/2012/09/20/rec/
  • Join an online initiative to go complaint free for one month and induce positivity in your life https://gonoco.com/
  • Easily distracted? Having trouble finishing meaningful tasks? Try a 30/30 timer rule: switching tasks every 30 minutes. There are iOS apps that time you and chime for you to make a switch and move on. http://3030.binaryhammer.com/

Password Security and Privacy

  • Check if your email has been hacked https://haveibeenpwned.com/
  • Controls what google knows about you
    • http://venturebeat.com/2015/11/10/googles-new-about-me-tool-lets-you-control-personal-information-shown-by-gmail-youtube-maps-and-more/

Social Network, Social Marketing and Growth Lifehacks

  • Use Tweepi to flush Twitter followers that are inactive or don't follow you back

Personal Finance Productivity

  • Use a stock, mutual fund screener to find stocks and funds that match your investment goals for your 401K plan

Developer Productivity:

  • Pair programming for productivity - AirPair and Pivot Labs, a premium development consulting agency for startups and new technology companies, talk about pair programming for developer productivity http://www.airpair.com/pair-programming/
  • Use code lint, code validation, and auto formatting (such as Android Studio code formatting) to get error free codes
  • Always look for shortcuts and do more things faster. Some developers even use fast notetaking apps like notational velocity and combine it with hot keys to shave fraction of seconds off their daily routine. 
  • Code a mobile app without learning iOS development or Android ionic framework http://ionicframework.com/

Startup Productivity

  • Use prototype and wireframes as visual aid to communicate product visions and designs, clearly. 
  • Did you know that having a 3D printed prototype generate 3x more feedback for architecture and physical product designers than just having a concept drawing? 
  • Did you know that famous universities like Stanford teach students to print or draw iOS UIs and designs on paper and walk user through imaginary steps to get design feedback before they code?
  • Looking for great business ideas? Use a startup name or domain generator to get inspired!
  • Google design often teaches paper prototyping - fast, easy-to-use and effective


    This Week in Silicon Valley Byte Size Newsletter No.101

    Udacity Launches AI for trading with WorldQuant, also its hiring partner. Ready to do artificial intelligence for fintech, this may be your nanodegree! What's the ultimate dream? Probably join a quantitative traded hedge fund, eventually. It is said that a little less than 30% of all US trades are done by computers. Specifically you want python for finance and historical data skills.
    - https://blog.udacity.com/2018/08/introducing-the-artificial-intelligence-for-trading-nanodegree-program.html

    Author Adam Fisher launches Valley of Genius as told by the hackers, founders, and freaks who made it. If you like HBO's Silicon Valley, you will probably like these unicorn and innovator stories of Silicon Valley


    Great Escape! Medium is running an August author challenge: tell Medium why and how you quit your job! https://medium.com/s/greatescape/tell-us-about-the-best-time-you-quit-your-bad-job-aaaf6d5b4e20 Your story may be featured. See this challenge post by Medium's editor.
    - https://medium.com/s/greatescape

    What does it feel like to be Steve Job's daughter? Her memoir now available for readers. See this article on Vanity Fair.
    - https://www.vanityfair.com/news/2018/08/lisa-brennan-jobs-small-fry-steve-jobs-daughter




    Youtube Machine Learning Artificial Intelligence celebrity Sraj wants to start his own School of AI. He wants it to be a "nonprofit". Strange but true. He's now recruiting Deans to head cities.





    Business Intelligence Data Warehousing BIDW Basics 101

    BIDW may employ more stable, heavy duty and less flexible architecture, schema and data store than startups in the Silicon Valley. Such may be a sacrifice for security, stability which many fortune companies rely on.

    Structured Query Language (SQL)

    Despite the popularity of many new data stores and technologies such as Hadoop, Spark, Pandas etc, many companies still require Business Analysts to be fluent in sql. Never forget SQL.

    Graphical User Interface (GUI)

    GUI interface helps business users query and drill data without the help of the development department. The schema and database are still designed and implemented by dev.


    Online Analytical Processing (OLAP)

    Provides a GUI to query platform for business users to do data explorations with minimum help from dev department. 

    Analysts and decision makers can quickly and efficiently do data analysis and ad hoc reporting without too much help from a data scientist or database administrator. 

    The schema, reports, and drilling depth may need to be pre-planned, designed and tested before being released to business users.

    This is also a large scale system, suitable for companies such as Macy's, Gap, Walmart which have millions of new sales record per hour. 

    OLAP is for data exploration by large businesses.

    Data Warehousing 

    Data Warehousing is a serious challenge for large companies with many transactional records, product offerings across many departments. 

    Many DW providers can also provide integrated data mining, business intelligence services build on top of proprietary DW hardware (including server stack) and software.

    Best Practice

    • Sales teams on-the-road often needs faster, better data information on mobile devices to seal a deal. Don't be surprised if they get mad when numbers are off! They bring home the dough. 

    Questions that Business Analysts and Decision Makers are Interested In

    • Who are the best customers? aka Who are the customers with the best Customer Life Value
    • Causal relationship: 
      • Results of recent experiments (More prevalent in Startup Culture)
      • Hypothesis if one segmentation is actually different from another
      • Is the result significant or is it random chance
      • Please note that causal relationship determination requires controlled studies to control for extraneous variables. In many industries, such as biotech, statistical significance is a must, a prerequisite for next step analysis or more business investments. 
      • Demo graphics of customers. Summary statistics, customer segmentation and more. 
      • How to measure profitability and other Key Performance Indicators (KPI)

    SQL Basics 101

    SELECT, INSERT, UPDATE with SQL

    The Equivalent of HelloWorld of SQL

    SELECT *
    FROM table_name

    Select all columns and rows from a table. In real life practice, we may want to avoid using SELECT * because it may be asking and displaying a lot of unnecessary records utilizing our precious computing resource, especially for large systems, companies with large databases. 

    A Basic Select Statement

    SELECT ProductID, Name
    FROM Product
    WHERE Price > 2.00


    A Fancier Select Statement

    SELECT * FROM CUSTOMERS WHERE AGE > 25 AND SEX = 'F' AND REGION='CA'

    The *  means all, specifically all columns and rows in this statement. All columns and all rows will be returned. 

    An Advanced Select Statement with Join Statement

    SELECT p.[Name] AS ProductName,
    c.[Name] AS CategoryName,
    FROM SalesLT.Product AS p
    JOIN SalesLT.ProductCategory AS c
    ON p.ProductCategoryID = c.ProductCategoryID;

    An Insert Statement


    INSERT INTO table_name (column1, column2, column3, ...)
    VALUES (value1, value2, value3, ...);



    Useful SQL interview skills

    Be able to read and comprehend SQL scripts

    Be able to compose advanced sql queries including aggregation, slicing and dicing.

    Advanced SQL Query Select Count and Group By

    It's easy to use SQL to display all the data columns and rows. But that's not practical. It's not practical for the business user to get the entire database, nor is it memory efficient. 

    How to view aggregate data? Use Group By, don't forget to use Count() too, else the result is again not meaningful. 

    SELECT COUNT(CUSTOMER_ID), STATE
    FROM CUSTOMERS
    GROUP BY STATE
    ORDER BY COUNT(CUSTOMER_ID) DESC;

    Group By helps aggregate and filter out data. In this case we are interested in aggregating data by State in the Customers table. What kind of state wide information are we trying to get? We are trying to count the number of customers in each state, as measured by customer_id. In addition, once data is aggregated, order the results in a descending order by count(customer_id) the largest count to the smallest. 

    Compare a Select all statement which just returns all the data rows
    to
    Select Count() and Group By statement that aggregates data by country



    SQL is great for the following queries:


    • SQL Segmentation example, analyze by location, select * from sales group by location

    Additional Tools

    Why should you learn SQL - common SQL usage

    Swift iOS Development Core Data uses sqlite as a persistent data store.

    Alternatives to SQL language, sqlite, and relational databases
    • ORM and ActiveRecords used in Rails
    • Hadoop uses HIVE is a SQL like language
    • Spark and the new way to run SQL queries on structured, distributed data
    • Firebase real time database and JSON
    • JSON objects
    • NoSQL databases like MongoDB

    SQL Security
    Cross Site Scripting and SQL Injection
    If allowed to enter special characters in input boxes and forms on a website, hackers may use code to run SQL queries against your database and get data illegally about your website. Many websites do not allow special characters, such as yelp. Some websites stringify the user input before processing it on the server so special characters are turned into strings so to reduce security risk. 

    Saturday, August 4, 2018

    3D Printing Basics 101

    Learn how to 3D Print with Shapeways - Getting Started with 3D Printing

    Take a 3D printing class with shapeways - a famous European printing house http://www.skillshare.com/classes/design/Introduction-to-3D-Printing-An-Easy-Start-to-Your-First-3D-Design/2097968974

    My personal favorite app to get started is TinkerCAD. You don't need to know 3D modeling to get started.

    Getting Started with 3rd Party Printing

    Here are just a few of the ways our 3D tools make it easy to 3D print with Shapeways:

    1. Check to make sure your design is ready for 3D printing
    2. Reinforce designs that are too thin
    3. Identify loose shells in a 3D scan
    4. Save on labor cost by adding a sinter shell container to multi-part designs
    5. Get feedback from our engineers if we're unable to manufacture your design
    Note shapeways mail from Europe. 

    Useful Apps


    • 123D Scan - an app that can scan real world object into 3D object
    • Shapeways 3D printing model checking tool

    Password protect and zip compress files on Mac

    The following step is only recommended for developers who have experience working in the command line. This is the build-in zip compress and...