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Started this discussion. Last reply by Yuecai Zhu Apr 22, 2016. 4 Replies 0 Likes

In the past few months, I have scripted with python for my job. I am really satisfied with its dynamic data type feature and the ease of using list. But then today in an interview for a job, the…Continue

Yuecai Zhu replied to Vincent Granville's discussion The Guide to Learning Python for Data Science

"Hi Vincent,
You forget to mention Spark Python API in your tutorial, which is for big data processing and analysis.
Also, a real data scientist should know sql, instead of learning pandas, I would suggest to learn sql.
Thanks"

Apr 22, 2016

Yuecai Zhu replied to Yashu Gupta's discussion Is there any Open Source Data Mining Tool for Creating Decision Trees ?

"scikit-learn is a machine learning library in python.
If you need to repeat your job many times and your data is stored in a database instead of just a csv file, then I recommend to write a script for this. It can also output the…"

Apr 22, 2016

Yuecai Zhu replied to Yuecai Zhu's discussion Python is bad for beginner

"Yes, numpy is cool in efficiency. And the numpy array behave similar as array in c/c++ and java.
But if you use numpy array, then why you use python? numpy array is static typed, it can only store elements of the same type. While python list…"

Apr 22, 2016

Alex Bozhkov replied to Yuecai Zhu's discussion Python is bad for beginner

"Let me disagree with author, NumPy has all required stuff for matrices and array ops"

Jun 12, 2015

Ken Lai replied to Yuecai Zhu's discussion Python is bad for beginner

"I have opposite opinion about Python.
I think C/C++ or java has higher learning curve than Python, which is quite superb on prototype and fast development.
Also there are a lot of module for heavy calculating and parallel computation.
My previous…"

Oct 25, 2014

nw replied to Yuecai Zhu's discussion Python is bad for beginner

"I thought numpy was just that, arrays."

Oct 24, 2014

Yuecai Zhu's discussion was featured### Python is bad for beginner

In the past few months, I have scripted with python for my job. I am really satisfied with its dynamic data type feature and the ease of using list. But then today in an interview for a job, the interviewer asked an algorithm question which need to use array and linkedlist to solve. I found that it is hard for me to think in array (there is no array in python, list is the one substitutes, but you don't need to know the length). Therefore I think python may not be a good starting language,…See More

Oct 4, 2014

Yuecai Zhu replied to Amitesh Kumar's discussion Logistic regression intercept term not significant

"In my opinion, intercept means unknown factors and error when estimating coefficients in the linear phase . This may be caused by the noise in your training data set if it is mainly error. I think you can try to clean the data and try to add more…"

Oct 2, 2014

Yuecai Zhu's blog post was featured### comparative study note of Python and Java 4 --Function and Polymorphism

Function and PolymorphismThe Hovering QuestionWhen I started learning these two languages, as mentioned before, I always keep in mind that the difference between dynamic data type and static data type. Then the question came out: why they need to be like that? What is the advantage of being dynamic data type or being static data type? To make the question more concrete, let’s see how to define a function in both languages.In Java, everything is very straight forward:…See More

Dec 18, 2013

Yuecai Zhu posted a blog post### comparative study note of Python and Java 4 --Function and Polymorphism

Function and PolymorphismThe Hovering QuestionWhen I started learning these two languages, as mentioned before, I always keep in mind that the difference between dynamic data type and static data type. Then the question came out: why they need to be like that? What is the advantage of being dynamic data type or being static data type? To make the question more concrete, let’s see how to define a function in both languages.In Java, everything is very straight forward:…See More

Dec 16, 2013

Yuecai Zhu's blog post was featured### A summary on Maximum likelihood Estimator

A summary on Maximum likelihood Estimator Why to learn MLE?The drawback of least square estimatorA general method of building a predictive model requires least square estimation at first. Then we need work on the residuals, find the confidence interval of parameters and test how well the model fits the data which are based on the normally distributed assumption of the residuals (or noises). But unfortunately the assumption is not guaranteed. Most of the time, you will have a graph of residuals…See More

Nov 28, 2013

Yuecai Zhu posted a blog post### comparative study note of Python and Java 3 - Sequence type

3. Sequence Type This time, we compare the sequence types of the two languages. By the terminology sequence type, we mean the data structure that is kind of a sequence of data.In Java, we have: String, array, list(arraylist and linkedlist), set;In Python, we have: Str, tuple, list, set;Yes, String is one of the sequence type, because it is a sequence of char, isn’t it? About the Sting type, we only need to know its implementation is the same in both languages, and that’s it.I:array vs…See More

Nov 16, 2013

Yuecai Zhu commented on Yuecai Zhu's blog post comparative study note of Python and Java 3 - Sequence type

"Thanks for your complememt Davide. When I check the Java api, I skipped these two methods because of the boolean return type.
When apply c.retainAll(b) and c.addAll(b), the set c will be modified to be the result(the intersection or the union…"

Nov 15, 2013

Davide Imperati commented on Yuecai Zhu's blog post comparative study note of Python and Java 3 - Sequence type

"Nice comparison, it is a good guide to the choice of a programming language.In Java, set operations can be performed using addAll(.) for the union and retainAll(.) for the intersection
e.g. c <- a intersection b is:
Set<...> c = new…"

Nov 15, 2013

Yuecai Zhu's blog post was featured### comparative study note of Python and Java 3 - Sequence type

3. Sequence Type This time, we compare the sequence types of the two languages. By the terminology sequence type, we mean the data structure that is kind of a sequence of data.In Java, we have: String, array, list(arraylist and linkedlist), set;In Python, we have: Str, tuple, list, set;Yes, String is one of the sequence type, because it is a sequence of char, isn’t it? About the Sting type, we only need to know its implementation is the same in both languages, and that’s it.I:array vs…See More

Nov 14, 2013

Yuecai Zhu posted a blog post### comparative study note of Python and Java 3 - Sequence type

3. Sequence Type This time, we compare the sequence types of the two languages. By the terminology sequence type, we mean the data structure that is kind of a sequence of data.In Java, we have: String, array, list(arraylist and linkedlist), set;In Python, we have: Str, tuple, list, set;Yes, String is one of the sequence type, because it is a sequence of char, isn’t it? About the Sting type, we only need to know its implementation is the same in both languages, and that’s it.I:array vs…See More

Nov 10, 2013

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Posted on December 16, 2013 at 1:30pm 0 Comments 0 Likes

Function and Polymorphism

When I started learning these two languages, as mentioned before, I always keep in mind that the difference between dynamic data type and static data type. Then the question came out: why they need to be like that? What is the advantage of being dynamic data type or being static data type? To make the question more concrete, let’s see how to define a function in both languages.

In Java, everything is very…

ContinuePosted on November 28, 2013 at 8:00am 0 Comments 0 Likes

A summary on Maximum likelihood Estimator

The drawback of least square estimator

A general method of building a predictive model requires least square estimation at first. Then we need work on the residuals, find the confidence interval of parameters and test how well the model fits the data which are based on the normally distributed assumption of the residuals (or noises). But unfortunately the assumption is not guaranteed. Most…

ContinuePosted on November 10, 2013 at 12:00pm 2 Comments 0 Likes

3. Sequence Type

This time, we compare the sequence types of the two languages. By the terminology sequence type, we mean the data structure that is kind of a sequence of data.

In Java, we have: String, array, list(arraylist and linkedlist), set;

In Python, we have: Str, tuple, list, set;

Yes, String is one of the sequence type, because it is a sequence of char, isn’t it? About the Sting type, we only need to…

ContinuePosted on October 30, 2013 at 5:32pm 0 Comments 0 Likes

Now we try to use the two languages to do a practice. The following, one in Java one in Python, are two programs with the same algorithm.

/*

* program author: __Yue__ __Cai__ __Zhu__.…

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