jueves, 22 de julio de 2010

My country, Colombia. Watch it!



The Republic of Colombia includes the northwestern part of South America. It is situated within the tropical zone, and is bounded on the north by the Caribbean Sea on the east by Venezuela and Brazil, Ecuador and Peru south and west by the Pacific Ocean and the Republic of Panama.

ITERATIVE METHODS FOR SOLVING SYSTEMS OF LINEAR EQUATIONS





Iterative method

In computational mathematics, an iterative method attempts to solve a problem (for example, finding the root of an equation or system of equations) by finding successive approximations to the solution starting from an initial guess. This approach is in contrast to direct methods, which attempt to solve the problem by a finite sequence of operations, and, in the absence of rounding errors, would deliver an exact solution (like solving a linear system of equations Ax = b by Gaussian elimination). Iterative methods are usually the only choice for nonlinear equations. However, iterative methods are often useful even for linear problems involving a large number of variables (sometimes of the order of millions), where direct methods would be prohibitively expensive (and in some cases impossible) even with the best available computing power.



*GAUSS-SEIDEL




*METHOD OF JACOBI


REFERENCES:

(1)NUMERICAL METHODS FOR ENGINEERS WITH PERSONAL COMPUTER APPLICATIONS. STEVEN C. Chapra / Raymond P. CANALE

(2) internet-google.

(3)Enciclopedia libre wikipedia

miércoles, 21 de julio de 2010

LU decomposition



LU decomposition

This type of factorization is useful for solving systems of equations.
Resume Gaussian elimination process applied to the matrix.

In linear algebra, the LU decomposition is a matrix decomposition which writes a matrix as the product of a lower triangular matrix and an upper triangular matrix. The product sometimes includes a permutation matrix as well. This decomposition is used in numerical analysis to solve systems of linear equations or calculate the determinant.




REFERENCES:

(1)NUMERICAL METHODS FOR ENGINEERS WITH PERSONAL COMPUTER APPLICATIONS. STEVEN C. Chapra / Raymond P. CANALE

(2) internet-google.

(3)Enciclopedia libre wikipedia

martes, 20 de julio de 2010

METHODS FOR THE SOLUTION OF SYSTEMS OF EQUATIONS.




The matrix algebra is used to solve systems of linear equations. In fact it is used in various mathematical procedures as the solution of a set of nonlinear equations, interpolation, integration and differentiation which are reduced to a set of linear equations.



SIMPLE GAUSS

The method of Gauss to be the German mathematician Johann Carl Friedrich Gauss, is a generalization of the reduction method, which we use to eliminate an unknown quantity in the systems of two equations with two unknowns. It consists of the successive application of the method of reduction, using the criteria of equivalence of systems, to transform the augmented matrix with independent terms in a triangular matrix, so that each row (equation) have a mystery unless the immediately preceding . This provides a system, which we call step, such that the last equation has a single unknown, the last but two unknowns, the penultimate three unknowns, ..., and the first all unknowns.

The operations we can do this matrix to transform the initial system into an equivalent are:

• Multiply or divide a row by a nonzero real number.
• Add or subtract a row another row.
• Add a row another row multiplied by a nonzero number.
• Change the order of the rows.
• Change the order of the columns that correspond to the unknowns of the system taking into account the changes made at the time of writing the new equivalent.
• Delete rows that are proportional or linear combination of others.
• Delete rows zero (0 0 0 ... 0).



See the example in the following document..




GAUSS-JORDAN

This method is a variant of Gauss elimination method. The main difference with this is that when a mystery is removed from an equation in the Gauss-Jordan, this is eliminated in all equations of the system rather than being limited to the subsequent equations.

The method generates an identity matrix and therefore do not need the back substitution process. It should be noted that the method can present the same difficulties that the method of simple Gaussian elimination.





SPECIAL METHODS

Arrays are widely used in computing, ease and lightness to manipulate information. In this context, the best way to represent graph, and are widely used in the numerical calculation.

Attached is a presentation with an explanation and rationale of two methods empeciales:

• Thomas Method
• Cholesky Method


These two methods are easy to program in any programming language, Microsoft Excel is recommended.



REFERENCES:

(1)NUMERICAL METHODS FOR ENGINEERS WITH PERSONAL COMPUTER APPLICATIONS. STEVEN C. Chapra / Raymond P. CANALE

(2) internet-google.

(3)Enciclopedia libre wikipedia

Basic concepts. Systems of equations




Before continuing our study of systems of equations is necessary to consider some concepts on determinants and matrices. Mathematical operations, etc.



REFERENCES:

(1)NUMERICAL METHODS FOR ENGINEERS WITH PERSONAL COMPUTER APPLICATIONS. STEVEN C. Chapra / Raymond P. CANALE

(2) internet-google.

(3)Enciclopedia libre wikipedia

SYSTEMS OF LINEAR EQUATIONS




Systems of linear equations

In mathematics and linear algebra, a system of linear equations, also known as linear system of equations or simply linear system is a set of linear equations over a field or a commutative ring. An example of linear system of equations is as follows:



The problem is to find the unknown values of the variables x1, x2 and x3 that satisfy the three equations.

SYSTEM TYPES

Systems of equations can be classified according to the number of solutions that may occur. According to that case may have the following cases:

Incompatible system if it has no solution.
System compatible if you have any solution in this case can also distinguish between:

-Determined when compatible system has a finite number of solutions.
-Compatible system supports indefinite when an infinite set of solutions.

Staying well classification:



REFERENCES:

(1)NUMERICAL METHODS FOR ENGINEERS WITH PERSONAL COMPUTER APPLICATIONS. STEVEN C. Chapra / Raymond P. CANALE

(2) internet-google.

(3)Enciclopedia libre wikipedia

viernes, 16 de julio de 2010

CALCULATION OF MULTIPLE ROOTS AND COMPLEX ROOTS




CALCULATION OF MULTIPLE ROOTS AND COMPLEX ROOTS

When there are complex roots closed methods can not be used as the criterion for defining the range is the sign change does not apply to complex values.

For this reason, special methods have been developed to find real and complex roots of polynomials.

• MULLER'S METHOD
• THE BAIRSTOW METHOD


*MULLER METHOD:

The secant method obtains an approximation of the root leading a straight line to the axis X with two values of the function. Muller's method is similar, but building a parabola with three points.

The method consists of obtaining the coefficients of the parabola through the three points. These coefficients are used in the quadratic formula to get the value where the parabola intersects the X axis, ie the estimated result.

Once you know the approximate coefficients found through the root of the quadratic equation where:



Having to solve the quadratic to find the new result leaves open the possibility that complex roots can be calculated, where i = root of -1.

As a general rule is to choose the root whose discriminant D1 or D2
is the largest since this ensures that the new root is closest to the initial values proposed










*Bairstow Method



REFERENCES:

(1)NUMERICAL METHODS FOR ENGINEERS WITH PERSONAL COMPUTER APPLICATIONS. STEVEN C. Chapra / Raymond P. CANALE

(2)http://www.concepcionabraira.info/wp/?p=305

(3) internet-google.

(4)Enciclopedia libre wikipedia