Mathworks is the leading developer of mathematical computing. I need to find all possible divisors d for a given number n that provide integers in nd. The following tool visualize what the computer is doing stepbystep as it executes the said program. Gcd of numbers and polynomials matlab gcd mathworks. How to sum up row values in a matrix learn more about row, matrix, sum. Divisor of numbers is meant integer that divides the number without a remainder. The number 6 is perfect since its factors other than 6 are 1. Find all divisors of a natural number set 1 geeksforgeeks. Divisor power sum function is the sum of the powers of all the positive divisors. So d gets the divisors for all numbers between 1 and n inclusive.
You can use double precision numbers or numbers converted to symbolic objects. I have n 3x3 matrices b, and i want to construct another 3x3 matrix a in which each entry is the sum of the similar entries of the initial 3x3 b matrices. There is actually a less known recursive formula for calculating. Amicable numbers are two different numbers so related that the sum of the proper divisors of the one is equal to the other, one being considered as a proper. Betrothed numbers are two positive numbers such that the sum of the proper divisors of either number is one more than o. Mathworks is the leading developer of mathematical. Divisors of integer or expression matlab divisors mathworks. The aliquots of a number, or aliquot parts, are all of the proper divisors of that number. Divisors of a number, perfect, amicable, and sociable. The mupad numlib library contains the functions that support this task.
These functions return all divisors, the sum of all divisors, the number. The sum of the prime divisors of a prime number returns the original number. The divisor sum function is the divisor power sum function. If a is a vector, sum a returns the sum of the elements. Follow 85 views last 30 days sahar abdalah on 11 apr 2015. From here we can generate perfect numbers, abundant numbers, deficient numbers, amicable numbers, sociable numbers, etc.
Heres a reference with more information from wikipedia. Matlab live scripts support most mupad functionality, although there are some differences. Divisorsumn, form represents the sum of formi for all i that divide n. Given a natural number n, print all distinct divisors of it. In general, if you have the prime factorization of the number n, then to calculate the sum of its divisors, you take each different prime factor and add together all its powers up to the one that appears in the prime factorization, and then multiply all these sums together. What would it mean if a number had no remainder with respect to 2, or 3, or 4. Write a matlab program that checks whether a given number is semiperfect. Divisorsumn, form, cond includes only those divisors for which condi gives true. Sum of squared elements of matrix or matrices matlab. If the argument native is given, then the operation is performed in the same type as the.
Cody is a matlab problemsolving game that challenges you to expand your knowledge. It also has links to calculators for other number theory functions such as eulers totient function. I am new to matlab and for the values of a, l and w i need to find all the values for l in the data set and the corresponding w values. Euler phifunction is defined as the number of integers less than or equal to that are relatively. If you want numerical values then the calculator at the site below will list all divisors of a given positive integer, the number of divisors and their sum.
If a and b are of different types, then g is returned as the nondouble type. How can i find and show divisors of n learn more about finding divisors. You already used modn, 1 to find out whether the number has a remainder with respect to 1. Sum of absolute elements of matrix or matrices matlab. Nov 17, 2011 i need to find all possible divisors d for a given number n that provide integers in nd. As far as efficiency is concerned you should first generate a list of divisors 12 2,2,3 then group them 2,2,3 then apply product of sets see here. The function is pretty fast and returns correct output. G is the same size as a and b, and the values in g are always real and nonnegative. For details, follow the matlab sum page symsum finds the sum of a symbolic series. If a is a matrix, sum a treats the columns of a as vectors, returning a row vector of the sums of each column. Find divisors for a given number matlab answers matlab. On the contrary, if double is given, the sum is performed in double precision even for single precision inputs for double precision inputs, the extra option will use a more accurate algorithm than straightforward summation. In matlab sumx adds all elements of matrix x in one dimension.
Returns sum of all divisors of a number w3resource. In the main function u, the first line assigns the sum of all squared divisors to m. Find divisors for a given number matlab answers matlab central. If you do not specify k, symsum uses the variable determined by symvar as the summation index. Amicable number file exchange matlab central mathworks. How to develop a defensive plan for your opensource software project. Calculator to calculate the set of all divisors of given natural number. Greatest common divisor, returned as an array of real nonnegative integer values. I m solving a problem to find the sum of divisors of a given numberthe number is a large one. Contentsfinding all the divisorstry some more numberswhats wrong now. How to use sum series in matlab matlab answers matlab central. Divisible by n, composite divisors matlab cody matlab central.
When the sum of all divisors of a positive integer, except the number itself, equals the number. Note that this problem is different from finding all prime factors. Find sum of divisors of all the divisors of a natural number. Determine if input is a perfect number matlab cody matlab. We can count the number of proper divisors using aliquotsum too. A perfect number occurs whent the sum of all divisors of a positive integer, except the number itself, equals the number. If you call divisors for a doubleprecision number, then it returns a vector of doubleprecision numbers.
If f is a constant, then the default variable is x. Mathworks is the leading developer of mathematical computing software for engineers and scientists. Prime numbers less than or equal to input value matlab. The aliquot sum sn of n is the sum of the proper divisors that is, the divisors excluding n itself, oeis. Determine if given number is perfect matlab cody matlab. I stumbled upon this while looking for a fast custom way to calculate every divisors of a number given its prime factors. F symsumf,k,a,b returns the sum of the series f with respect to the summation index k from the lower bound a to the upper bound b. So, given a number n, by prime factorization we can find the sum of divisors of all the divisors. These functions return all divisors, the sum of all divisors, the number of divisors, and the number of prime divisors. To find the greatest common divisor of rational or complex numbers, convert these numbers to symbolic objects by using sym, and then use gcd. How to do a sum of a function over all divisors of an. Sum of fi array elements matlab sum mathworks espana. Also related is the divisor count function, which is also denoted or. How to do a sum of a function over all divisors of an integer.
Follow 446 views last 30 days atinesh s on 10 apr 2015. Heres one example of a simple program to find the primes less than any number mathnmath. For faster still, hint 3 is that you only have to do this up to n3 you have 2x the sum of the range from n3 to n2 and then all of the range from n2 to n. How to use sum series in matlab matlab answers matlab.
S suma,vecdim sums the elements of a based on the dimensions specified in the vector vecdim. Finding all the divisorsyou may think that all we need to. Can you write a program to calculate the sum of all the prime. S sum a returns the sum along different dimensions of the fi array a. If you have an array of a different type, such as double or single, then you can convert that array to an array of type int64 by using the int64 function. This problem has very simple solution, we all know that for any number. To do this, one can use a formula which is obtained by summing a geometric series.
This function uses the default factor routine in matlab and hence. Find sum of divisors of all the divisors of a natural. How can i find the sum of divisors of a given number in a. I have recently stumbled upon somebody elses code which used a function for calculating sum of divisors of a certain number. The matlab gcd function does not accept rational or complex arguments. Sum of all proper divisors of a natural number geeksforgeeks. Number of divisors function number of divisors sum of divisors function sum of divisors. If a is a vector, suma returns the sum of the elements if a is a matrix, suma treats the columns of a as vectors, returning a row vector of the sums of each column if a is a multidimensional array, suma treats the values along the first nonsingleton dimension as vectors, returning an array of row vectors. There is a wellknown formula for the sum of all of the integers up to n, that provides a short circuit. Algorithm for getting all divisorsreferences and linkshave you had some fun with number theory in matlab.
Is there a formula to calculate the sum of all proper. I speak about the sum of fd, where d goes through the set of all divisors of n for a function f. A naive solution would be to iterate all the numbers from 1 to n, checking if that number divides n and printing it. Given a natural number, calculate sum of all its proper divisors. Greatest common divisor matlab gcd mathworks india.
This matlab function returns a row vector containing the prime factors of n. This matlab function takes a matrix or cell array of matrices and returns, sum of all absolute finite values number of finite values. If one knows the factorization of a number, one can compute the sum of the positive divisors of that number without having to write down all the divisors of that number. This matlab function takes a matrix or cell array of matrices and returns, sum of all squared finite values number of finite values. If you want to just calculate the sum for one specific dimension use.
I know this was 3 months ago but as an experiment because i am new to python i decided to try and combine some of the other people answers and i came up with a method you can pass the max number to and the divisors as a list and it returns the sum. All you need to do is find the prime numbers less than 100, and add them all up. A proper divisor of a natural number is the divisor that is strictly less than the number. Unlike the matlab sum, the symbolic sum function does not work on multidimensional arrays. The second line gets the divisors for m and determines if any of them squared equals m. But in this problem we are given that n is product of element of array. For example, if a is a matrix, then suma,1 2 is the sum of all elements in a, since every element of a matrix is contained in the array slice defined by dimensions 1 and 2. Divisible by n, composite divisors matlab cody matlab. A number is perfect if it is equal to the sum of its factors, excluding itself. Write a python program to returns sum of all divisors of a number. I wonder how to sum digits for a multidigit number in matlab. If you do not specify polynomial variables, divisors returns as many divisors as it can find, including the divisors of constant symbolic expressions. For instance, zeros100,int64 creates a 100by100 matrix of zeros of type int64.
644 517 1018 175 1192 1153 341 1377 196 1008 696 513 479 147 1035 1215 1240 1250 305 1379 275 1081 1025 122 963 334 978 495 1515 1317 58 78 1461 1141 1030 1420 772 1423 982 897 561