Author Archives: Ajitesh Kumar
Sklearn SVM Classifier using LibSVM – Code Example
In this post, you learn about Sklearn LibSVM implementation used for training an SVM classifier, with code example. Here is a great guide for learning SVM classification, especially, for beginners in the field of data science/machine learning. LIBSVM is a library for Support Vector Machines (SVM) which provides an implementation for the following: C-SVC (Support Vector Classification) nu-SVC epsilon-SVR (Support Vector Regression) nu-SVR Distribution estimation (one-class SVM) In this post, you will see code examples in relation to C-SVC, and nu-SVC LIBSVM implementations. I will follow up with code examples for SVR and distribution estimation in future posts. Here are the links to their SKLearn pages for C-SVC and nu-SVC …
Flutter – How to Create Dart Object from JSON
In this post, we will understand the concepts in relation to creating a Dart object from a JSON object and how to use these DART objects in Flutter app. We will build an app and run the code shown in this post. Here is an example JSON object which we will work with, in order to create a custom Dart object called as School. The JSON represents information about a school including name, address, departments. You may note that the JSON object is primarily of type Map<String, dynamic> where key is String and value is of dynamic type. The key, name, is of type <String, String>, the key, address, is of …
SVM – Understanding C Value with Code Examples
In this post, we will understand the importance of C value on the SVM soft margin classifier overall accuracy using code samples. In the previous post titled as SVM as Soft Margin Classifier and C Value, the concepts around SVM soft margin classifier and the importance of C value was explained. If you are not sure about the concepts, I would recommend reading earlier article. Lets take a look at the code used for building SVM soft margin classifier with C value. The code example uses the SKLearn IRIS dataset In the above code example, take a note of the value of C = 0.01. The model accuracy came out to …
SVM as Soft Margin Classifier and C Value
In this post, you will learn about SVM (Support Vector Machine) as Soft Margin Classifier and the importance of Value of C. In the previous post, we learned about SVM as maximum margin classifier. What & Why of SVM as Soft Margin Classifier? Before getting into understanding what is Soft Margin Classifier version of SVM algorithm, lets understand why we need it when we had a maximum margin classifier. Maximum margin classifier works well with linearly separable data such as the following: When maximum margin classifier is trained on the above data set with maximum distance (margin) between the closest points (support vectors), we can get a hyperplane which can separate the data in a clear …
Flutter – Map String Dynamic Code Example
In this post, we will understand the Flutter concepts related to Map<String, Dynamic> with some code example / sample. For greater details, visit Flutter website. Map<String, dynamic> maps a String key with the dynamic value. Since the key is always a String and the value can be of any type, it is kept as dynamic to be on the safer side. It is very useful in reading a JSON object as the JSON object represents a set of key-value pairs where key is of type String while value can be of any type including String, List<String>, List<Object> or List<Map>. Take a look at the following example: Above is an example of JSON object …
SVM Algorithm as Maximum Margin Classifier
In this post, we will understand the concepts related to SVM (Support Vector Machine) algorithm which is one of the popular machine learning algorithm. SVM algorithm is used for solving classification problems in machine learning. Lets take a 2-dimensional problem space where a point can be classified as one or the other class based on the value of the two dimensions (independent variables, say) X1 and X2. The objective is to find the most optimal line (hyperplane in case of 3 or more dimensions) which could correctly classify the points with most accuracy. In the diagram below, you could find multiple such lines possible. In the above diagram, the objective is to find the …
Security Misconfiguration Example – Upwork
In this post, you will see an example of security misconfiguration which is one of the top 10 security vulnerabilities as per OWASP top 10 security vulnerabilities. Here is what security misconfiguration means? Attackers will often attempt to exploit unpatched flaws or access default accounts, unused pages, unprotected files and directories, etc to gain unauthorized access or knowledge of the system. In this post, you will see the example of unauthorized knowledge of the system. Security Misconfiguration Example This morning, I was checking the Upwork.com when I saw this message when I tried to login. Take a look at exceptions and stack trace. Using the above, I could extract some …
Flutter Interview Questions for Beginners #1
This post is aimed to test your understanding on very basics of Flutter app development using most fundamental questions. It covers some of the following Flutter topics: Basic understanding of widgets and elements Basic understanding of stateful and stateless widgets
Flutter – When use Stateful vs Stateless Widgets
In this post, you will learn about when to use stateful widgets vs stateless widgets while building a Flutter app. Use Stateful widgets in case of the following scenarios. Note that the StatefulWidget instances themselves are immutable and store their mutable state either in separate State objects that are created by the createState method. When the part of UI which is described using the widget can change dynamically due to some of the following reasons: Due to user-interaction Due to database updates Due to system changes Use Stateless widgets in case of the following scenarios: When the part of UI which is described using the widget depends only on its configuration and the BuildContext in which the …
Flutter – GestureDetector Code Example & Concepts
In this post, we will learn about how to use GestureDetector with Stateful widgets in order to record changes to state. The following are key aspects in relation to changing state of the widget based on the users’ gesture. Capture user’s gesture using a widget called as GestureDetector. The following happens as part of GestureDetector widget: Capture events such as onTap, onDoubleTap etc and change the state After the user gesture is captured and the state is changed, the widget is built and replaced with existing widget. The existing widget is flagged as dirty. Here is the code representing the usage of GestureDetector for capturing user gesture, changing the state of the widget and …
Understanding Flutter Widgets with Code Examples
In this post, we will understand some of the following key concepts of Flutter framework. What are widgets? What are stateless widgets? What are stateful widgets? What are Flutter Widgets? A flutter mobile app consists of multiple UIs with each UI built out of one or more widgets. These widgets are nothing but elements of interaction between the app user and the application. Note element of interaction used to describe widget in Wikipedia definition given below. As per the wikipedia, A graphical widget (also graphical control element or control) in a graphical user interface is an element of interaction such as a button or a scroll bar. Controls are software components that a computer user interacts with through direct manipulation …
Flutter Hello World App, Concepts & Code Samples
In this post, we will look at quick code samples and related concepts for getting started with Flutter Hello World App. I think the best way to get quickly started without getting bothered about creating Android/iOS simulator or devices is to enable Flutter web app. One can follow instructions in this page related to Flutter web app commands cheat sheet to get started with Flutter web app. Here is the code for Flutter Hello World app. Place this code (replace with existing code created using template project) in lib/main.dart file to get started. Once done, execute the project using command such as following or run from the Android IDE. Basic Concepts for Understanding …
Flutter Web App Commands – Cheatsheet
In this post, I will list down some of the key commands (cheatsheet) which can help one build and release web application (app) using Flutter. In order for the following commands to work, follow the steps given below: Install Flutter: Make sure you have installed Flutter. Follow the steps in this page for setting up / installing flutter. Create Flutter Project: Once installed, create a template project for getting started with a project. Use this page for creating a flutter project. Flutter Commands for Web Once flutter is set up and a template project is created, execute the following one-time commands for setting up Flutter web development environment. These commands can be run from anywhere …
Top 5 Data Analytics Methodologies
Here is a list of top 5 data analytics methodologies which can be used to solve different business problems and in a way create business value for any organization: Optimization: Simply speaking, an optimization problem consists of maximizing or minimizing a real function by systematically choosing input values (also termed as decision variables) from within an allowed set and computing the value of the function. An optimization problem consists of three things: A. Objective function B. Decision variables C. Constraint functions (this is optional) Linear / Non-linear programming with constrained / unconstrained optimization Linear programming with constrained optimization Objective function and one or more constraint functions are linear with decision variables as continuous variables Linear programming with unconstrained optimization Objective function …
Contract Management Use Cases for Machine Learning
This post briefly represent the contract management use cases which could be solved using machine learning / data science. These use cases can also be termed as predictive analytics use cases. This can be useful for procurement business functions in any manufacturing companies which require to procure raw materials from different suppliers across different geographic locations. The following are some of the examples of industry where these use cases and related machine learning techniques can be useful. Pharmaceutical Airlines Food Transport Key Analytics Questions One must understand the business value which could be created using predictive analytics use cases listed later in this post. One must remember that one must start with questions …
Different Types of Classification Learning Algorithms
In this post, you will learn about different types of classification machine learning algorithms that are used for building models. Here are four different classes of machine learning algorithms for solving classification problems: Probabilistic modeling Kernel methods Trees based algorithms Neural network Probabilistic Modeling Algorithms Probabilistic modeling is about modeling probability of whethar a data point belongs to one class or the other. In case of need to train machine learning models to classify a data point into multiple classes, probabilistic modeling approach will let us model the probability of a data point belonging to a particular class. Mathematically, it can be represented as P(C|X) and read as probability of class C happening …
I found it very helpful. However the differences are not too understandable for me