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Numerical Analysis and Simulation

The study of algorithms for problems related to continuous mathematics

818 Questions

How is the last digit of a measurement different from the other digits?

the first number is usually in feet, the last number is in inches. so the last number = 1/12 of the first numbers value.

How many people play baseball in Spain?

In Spain baseball is not perfered sport. Sports like Soccer, basketball and rugby are top sports.

Approximately 23.

In how many ways can you arrange 6 things 3 at a time?

This is a Permutation problem; nPr is the formula which assumes order matters. You have n=6 & r=3. Formula is: 6! / (6-3)! or 6!/3! = 120.

Gaussian elimination in c?

#include<stdio.h>

#include<stdlib.h>

#include<math.h>

#include<conio.h>

void main(void)

{

int K, P, C, J;

double A[100][101];

int N;

int Row[100];

double X[100];

double SUM, M;

int T;

do

{

printf("Please enter number of equations [Not more than %d]\n",100);

scanf("%d", &N);

} while( N > 100);

printf("You say there are %d equations.\n", N);

printf("From AX = B enter elements of [A,B] row by row:\n");

for (K = 1; K <= N; K++)

{

for (J = 1; J <= N+1; J++)

{

printf(" For row %d enter element %d please :\n", K, J);

scanf("%lf", &A[K-1][J-1]);

}

}

for (J = 1; J<= N; J++) Row[J-1] = J - 1;

for (P = 1; P <= N - 1; P++)

{

for (K = P + 1; K <= N; K++)

{

if ( fabs(A[Row[K-1]][P-1]) > fabs(A[Row[P-1]][P-1]) )

{

T = Row[P-1];

Row[P-1] = Row[K-1];

Row[K-1] = T;

}

}

if (A[Row[P-1]][P-1] 0)

{

printf("The matrix is SINGULAR !\n");

printf("Cannot use algorithm --- exit\n");

exit(1);

}

X[N-1] = A[Row[N-1]][N] / A[Row[N-1]][N-1];

for (K = N - 1; K >= 1; K--)

{

SUM = 0;

for (C = K + 1; C <= N; C++)

{

SUM += A[Row[K-1]][C-1] * X[C-1];

}

X[K-1] = ( A[Row[K-1]][N] - SUM) / A[Row[K-1]][K-1];

}

for( K = 1; K <= N; K++)

printf("X[%d] = %lf\n", K, X[K-1]);

getch();

}

Significance of error analysis in numerical method?

Error analysis is absolutely critical to a successful numerical method. This is because, often, the method involves discrete numerical iteration, such as when solving a problem in integral calculus. Computers have errors in floating point representation, such as truncation and round-off. These errors can accumulate, and actually overwhelm the result.

For example, if your floating point format has 24 bit resolution (which is the size for a typical 32 bit float), adding 1 to 1×1025 will not change the result. If your program involves a loop, it could fail in this case. It is important to add and subtract numbers of comparable magnitude.

Another example is Taylor series, used for generating trignonometric functions such as sin(x). These series are most accurate between -pi/2 and +pi/2. If you were calculating sin(x) for large values of x, you would want to normalize x to be within that range by adding or subtracting 2 pi and then finally pi as needed. Problem is, that, at large values of x, 2 pi might only represent 1 or 2 bits of resolution, and your answer will be way off.

A third example is the solution of 3 equations in 3 unknowns. This represents three planes in 3-D space, which should, if not parallel, resolve to a single point. Error is measurement, and error in floating point representation, could easily (if two of the planes are nearly parallel) result in large error in the result.

The art is in balancing the accumulation of error against the increase in resolution as things become smaller and smaller, such as delta x when doing integration, a fourth example.

How many bps in 3.1 mbps?

The little ' m ' stands for 'mega' which is the same as 'million'.

So 3.1 mbps = 3,100,000 bps.

Is 0 a multiple of any number?

It depends for example:

0, 3, 6

This times table starts with 0.

3, 6, 9

This one does to it is just not included in the times table.

So yes 0 is a multiple of all numbers.

Why are frequency polygons used?

Frequency polygons are used to visually represent the distribution of a dataset, allowing for easy comparison of different groups or categories. By connecting the midpoints of class intervals with line segments, they provide a clear depiction of trends and patterns within the data. This graphical representation aids in identifying the shape of the distribution, such as normality or skewness, and is particularly useful for summarizing large datasets. Additionally, frequency polygons facilitate comparisons between multiple datasets on the same graph.

What is the use of gaussian elimination in real world situations?

The gaussian elimination is used to solve many linear equations with many unknown varaibles at once. [See related link below to find out how to do it]. This is used alot by engineers you know ceratin variables in there structures and want to find out what the stress and strain is in certain areas. They make up there linear equations and then they can use the gaussian elimination method to find the unknown variables.

How many 3 digit sets of numbers can be formed from the finite set of 12344?

This depends on whether you do mean sets or if you mean groups as the two are different and often people use the word set when they mean group. 24 groups can be formed and you can calculate this by using the permutation function. 4 possible elements to select from to go into 3 slots, 4P3=24 groups. (Note I said 4 elements not 5, as by definition an element can not be repeated in a set so the set is not {1,2,3,4,4} but {1,2,3,4} unless you mean {1,2,3,44} but this doesn't change anything.)

However, while 24 groups can be formed this is not true for sets, groups are structured unlike sets so a group of (1,2,3)≠(2,3,1), but a set{1,2,3}={2,3,1} i.e. the order of the elements matters in a group but not in a set, so only 6 sets of 3 elements can be made compared to 24 groups.

Can a trapezoid be a hexagon?

No. A trapezoid is a shape with four sides, while a hexagon is a shape with six sides.

What is the fourier transform of the Laplace operator of a function?

Let F(f) be the fourier transform of f and L the laplacian in IR3, then

F(Lf(x))(xi) = -|xi|2F(f)(xi)

What is 50 miles in numerals?

the number 50 is represented as "L" in numerals.

so... L miles

see related link below for more info on roman numerals

What is number system what are various number system explain with a suitable example?

A number system is simply a way to record numbers. Humans have used a variety of numbering systems over the years, but the decimal system is by far the most prevalent today. This system uses the ten Arabic symbols, 0123456789, to represent the digits from zero to nine, and is known as base 10 for this reason. Digits are aligned on columns, with units on the right, 10s to their left, and 100's to their left, and so on. Each column is therefore 10 times the value of the column to its right. In other words, each column is an increasing power of 10, beginning with 10^0 on the right, then 10^1 and so on.

You are undoubtedly familiar with base 10, however the above is relevant when discussing other number systems as the same principals apply.

Computers use base 2 (binary), which is the lowest base of all. It uses the 2 Arabic digits, 0 and 1. Since it is base 2, the columns represent powers of 2. So the rightmost column represents 2^0, then 2^1, 2^2, 2^3, and so on the further left we go. So the number 4 in decimal would be represented by 100 in base 2. That is, 1 * (2^2), which is 4 (all other columns are zero, so they evaluate to zero).

Computer programmers use base 16 (hexadecimal). This is because binary numbers, despite their apparent simplicity, are incredibly difficult for humans to work with. One digit out of place could be disastrous. Converting them to decimal is clearly an option, but hexadecimal is a lot simpler to work with because base 2 and base 16 are interchangeable and align with each other more closely than decimal.

Four binary digits gives us 16 possible combinations. 0000, 0001, 0010, 0011, 0100, 0101, 0110, 0111, 1000, 1001, 1010, 1011, 1100, 1101, 1110 and 1111 (decimal zero to decimal 15, respectively). With only 16 combinations to consider, each of these can be represented by a single hexadecimal symbol. There are only 10 Arabic symbols for numbers, so we must use 6 additional symbols for the numbers 10 to 15. By convention we use the letters a through f. Thus each of the binary combinations above can be represented by 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e and f, respectively.

Binary digits (bits) are usually combined into groups of 8 bits, known as bytes. 8 is a multiple of 4, so we need 2 hexadecimal digits to represent a full byte. To do this we simply divide the byte into two half bytes (known as nybbles), then convert each nybble to its hexadecimal form. Thus the byte 01101101 is represented as nybbles 0110 and 1101, which is 5d in hexadecimal (often denoted as 0x5d). This equates to (5 * (16^1)) + (13 * (16^0)), which is 93 decimal. So 01101101 is binary for 93 decimal, or 0x5d hexadecimal.

Regardless of the length of a sequence of bits, breaking them into groups of 4 allows them to be translated directly into hexadecimal. So a 32-bit number requires 8 hexadecimal digits. Reading and writing 8 digits is clearly a lot simpler than deciphering 32 bits of 1s and 0s, and because binary and hexadecimal have a consistent alignment (4 bits equals 1 hex digit), they are much easier to deal with than decimal which has a more variable alignment with binary (4 bits could be 1 or 2 decimal digits).

Other bases that are in common use today include base 60, which is the basis for our clocks. 60 seconds is 1 minute and 60 minutes is 1 hour. Then we switch to base 12 for the hours (or base 24 if using a 24-hour clock). You may ask why we never "decimalised" our time-keeping (dividing the day into 10 or 20 longer hours, each with 100 minutes, each with 100 seconds, for instance). The main reason is that 60 is evenly divisible by 2, 3, 4, 5 and 6, whereas 100 is evenly divisible by just 2, 4 and 5, and a 12-hour period (which is also division of 60) is evenly divisible by 2, 3, 4 and 6 whereas 10 is evenly divisible by just 2 and 5.

Inches and feet are also base 12. So while we are quite familiar with base 10, we actually use other bases without realising it. Of course we don't symbolise numbers greater than 9 with letters like we do in hexadecimal, but the principal is the same.

Develop an iterative formula to get a real root of x to the power 5 equals N Where N is a natural no greater than 1?

You do not need an iterative formula: just some logical thinking.

If N is a natural number that is no greater than 1, then N can only be 1.

There is only one real solution to x^5 = 1 and that is x = 1.

How many 1's and 0s can one byte of memory contain?

One byte is commonly accepted as holding eight bits. Therefore, one byte can hold eight 1's or eight 0's or anything in between, such as three 1's and five 0's.