Machine learning – Weeks 1-2

Really enjoying writing Matlab/Octave code for the Machine learning course.

It has been a while since I used Matlab. Was it during a signal processing course, or was it at the Air Force?

Can’t post my code, but can definitely post the result of my calculations.


Samples and Hypothesis
Samples and Hypothesis
Learning convergence depending on Alpha
Learning convergence depending on Alpha
Surface drawing of cost function
Surface drawing of cost function




Hope I can blog about this…

This blog is active for more than 5 years. Actually, active intermittently.

What I noticed is that although the traffic to my blog is almost the same level as it used to be 5 years ago, less people click on ads.

I don’t rely on ads to run my website nor do I expect to earn money, but I do want to figure it out.

Is my placement bad?

Are the ads chosen by Adsense not effective to my audience? -> How do I check that ?

Is it that users block ads or just don’t click ?


I don’t block ads, but I don’t think I clicked on one in the last month.


On Alerts

Yahoo Japan has an Alert applications which can provide Alerts to disasters, Weather as well as alerts on suspicious people.

Awareness is important. I am sure that such alerts can reduce the number of such events, as parents will report (and catch) suspicious people in the vicinity of the alert.

On the other hand, it is scary. I immediately check the location and try to figure out if my kids are in the neighbourhood.

I often hear that “it wasn’t like this back in the days”, but I truly think it is all about the availability of information.When I was a child we probably received a warning “stay away from that area, that man. he is strange”. We now get a warning about events as they happen including location.

In the image, a warning about a suspicious person, which performed some indecent act. Terms in Japanese are not clear enough to understand the nature of the act.

Yahoo alert

Amazon and iTunes MP3 prices

As I am interested in purchasing “Sleater Kinney” ‘s new album “No Cities to Love”, I checked Amazon Japan,  Amazon US and iTunes for prices.

Can’t understand why:

1. Japanese version has one additional song “The Fog and filthy Air”

2. Price is $7.99 in the US, while ¥1600 in Japan
(According to current currency rate, $7.99 should be ~¥950)

3. iTunes (Japan) is also ¥1600, but no additional song, just a booklet

Screen captures below

Sleater Kinney Amazon US
Sleater Kinney Amazon US


Sleater Kinney Amazon Japan
Sleater Kinney Amazon Japan


Sleater Kinney iTunes
Sleater Kinney iTunes


With the recent Technology “advances” of being online all the time, getting emails on smartphones, I feel we lost our accuracy.

Why bother being accurate and concise in emails when you can fix that later. We definitely engage more, respond more but it takes more of our time.

I try to practice the following when writing/answering emails:

1) Do I really need to send this over email? Can I get a better result with a simple call ? If so, call

2) Read again before sending. Is it clear enough ? Is my point or questions emphasised  correctly ?

3) Is my “To:” list good enough. Target , not broadcast

4) When responding, apply (2) but also Do I really need to respond to this ?


I was thinking about a credit system of each employee getting a specific “email credit” per day. For each email sent, the credit goes down until the employee is blocked to respond to urgent email only.

Obviously, this is difficult to implement without understanding the contents of the email. Would not like to block an employee from working, but still thinking how to improve effectiveness.




iPhone Google+

Maybe apparent from my age, but I remember the times when programmers were working extra time to make sure their application “weight” is minimal.
Either memory consumption or actual binary size (for embedded systems with limited storage).

Was surprised (shocked) to see the new Google+ update is 111MB.
Yes, 111MB of application which shows content from the web.
Not a game, Google+.

I assume it is due to Retina display graphics, but I still think this is not the right way to do it.
Application can get the necessary files after loading, can’t it? Why everyone need to waste storage for unnecessary data ?


On Literature and Twitter

Started reading Chihaya Akane’s “Male Friend”  (千早茜、男ともだち).

Though I am struggling a bit with slang and figure of speeches, I enjoy the writing.

Telling a story of a successful illustrator, cheating on her husband , meeting sometimes with her old University friend. A Male friend. I like the way she created the characters and tells their story, although I feel annoyance reading some parts.

Searched for information about the writer, I found her twitter page. I agree it is not that interesting, but was shocked to see she has only 1115 followers (well, 1116 if I decide to follow her as well).

There is something really strange in our culture if a valued writer has 1115 followers and a TV personality has 3.73 Millions

Chihaya Ariyoshi


Japanese Elections

As I can’t vote, I have little to no interest in the elections.

I do however have interest in the process, culture and discussions.

A few observations:

  1. None of my Japanese Facebook friends express their political opinions. This obviously in contrast to Israelis
  2. It is not surprising to bump into candidates in front of the train station talking, but very few people stand to listen (as they rush to work)
  3. The election cars are hilarious . Had an Israeli visitor this week and it took me sometime to explain the concept
  4. TV coverage is as boring as anywhere else in the world
  5. No Political comedy. None!