## Monday, July 29, 2013

### Anomaly Detection using Oracle R Enterprise (ORE) | SVM for Anomaly Detection

R is an open source scripting language and environment for statistical computing, data analysis & graphics.R provides an integrated suite of software facilities for data manipulation, calculation and graphical display- it's an integrated environment. Around 2 million users in the world are widely using R especially by corporate analysts & data scientists.

Anomaly/Outlier detection has wide applications. It can be used in fraud detection, for example, by detecting unusual usage of credit cards or telecommunication services. In addition, it is useful in customized marketing for identifying the spending behavior of customers with extremely low or extremely high incomes, or in medical analysis for finding unusual responses to various medical treatments.

## Wednesday, June 19, 2013

### Random Numbers Generation & Chi-Squared Test for their Uniformity in C++

Continuous uniformly distributed random numbers means the set of random numbers where probability of any number in any integral within a certain range of values is proportional to the ratio of the interval size to the range. The generated random numbers require to be independent & uniform in distribution. There are many different methods to generate the random numbers.
They are:
• Random numbers from table.
• From hardwired device.
• Using pseudo Number generation.

In linear congruential method, we use one initial number (rcalled seed) and few constants. Using the seed and the formula,
ri+1 = (ri ×a + b) (modulo m)

## Wednesday, June 12, 2013

### Determinant Calculation of Nth Order Square Matrix| Cramer's Rule Implementation in C

Determinant calculation of a square matrix is widely used in solving many applied Mathematics problems. Some of them are while solving a set of linear equations using Cramer's rule (iff they have unique solutions), calculation of inverse matrix, Eigen values/ Eigen vectors problem and so on.

The determinant of a square matrix A∈Rn×n is the real number det(A) defined as follows:

det(A) = SUMperm [sign(ν1,ν2,...,νn)a1ν1a2ν2...anνn]
.