Algorithm Definition and 651 Threads

First I'll try to give a summary of what I understand about the anti-##k_T## algorithm (as a continuation for a particle flow algorithm)... The algorithm uses an iterative clustering with transverse momentum ##p_T## weighted distance parameter and is applying a selection on the "protojets". For...

Hey! :o Lemma 1. For any $x$ in the ring $F[t,t^{-1}]$ ($F[t,t^{-1}]$: the polynomials in $t$ and $t^{-1}$ with coefficients in the field $F$), $x$ is a power of $t$ if and only if $x$ divides $1$ and $t-1$ divides $x-1$ (the divisibilities are meant, of course, in $F[t, t^{-1}]$). Lemma 2...

Homework Statement so for a side task I'm supposed to assign people to groups for an icebreaker in python, can anyone give me links to theories that I could read up on or give me suggestion X number of people at my company signed up for a dinner roulette as a way to meet new people. Everyone...

Hi, is there away to find values of m, x, and b for a given value of y. For example, if I have y = 10000, my 'm' could be 100, x = 100, and b = 0, or it could be m = 250, x = 40, and b = 0 or any other combination of m, x, and b. I need to write a C code for my microcontroller. I will be given...

HI everyone. I was just wondering about a career in the IT (I study communication systems engineering, but I'm rather interested in coding, rather than Internet and communcation systems- related stuff). I wanted to ask you, given the advances that technology is making, which skills would be...

Not sure if this is the correct place to post this type of question, so I will relocate if need be. What I'm interested in doing is taking an array of numbers and assigning a rank based on ascending order. Explicitly, the ranking of an array would look like 1.534 - 15 -0.887 - 3 -0.489...

http://qz.com/425662/picasso-genius-this-algorithm-can-judge-creativity-in-art-as-well-as-the-experts/

Homework Statement Hi - I'm on the last chapter of this book and am a bit stuck. I am given a very basic fortran program (code attached in the zip file) and asked to 'investigate its accuracy and stability, for various values of Δt and lattice spacings'. The program is an implementation of the...

Hey! :o I am studying Cryptology right now and I am facing some difficulties to understand the Pohlig-Hellman algorithm. Could you explain to me how the algorithm works?? Could you give me a step by step example?? (Wondering)

Hello! (Wave) I am looking at the following example of Memoized Dynamic Programming algorithm. memo={} Fib(n): if n in memo return memo[n] if n<=2 F[n]=1 else F[n]=F[n-1]+F[n-2] memo[n]=F[n] return F[n] Could you explain me why we check if $n$ is in memo although memo is a set...

Hi - on the last chapter of this course and was feeling much better about it all, but I now confess to being back in my normal state - confused. I am given a simple fortran program (code attached in the zip file) and asked to investigate its accuracy and stability, for various values of...

In the quest of searching what are the basic ingredients of quantum theory that provide exponential speed-up to some quantum algorithms, a basic question that is pursued in the literature is when a quantum circuit (or algorithm) can be classically simulated efficiently. One example is this paper...

Given a matrix A of a regular graph G. The matrix A can be divided into 4 sub matrices based on adjacency of vertex ##x \in G##. ## A_x## is the symmetric matrix of the graph ##(G-x)##, where ##C## is the symmetric matrix of the graph created by vertices of ##(G-x)## which are adjacent to...

Hi all, Im having trouble making a general algorithm for what at first glance appears to be a simple problem. If I have a volume (V) that can be made from two smaller, different volumes how can I decide which volumes to use to get the minimum wastage? So for example if V(required)=300 and my...

This is the core idea- https://www.physicsforums.com/threads/complexity-analysis-problem-of-an-algorithm.812931/ I would like to write a formal psudoecode (latex), but as new writer I am having hard time to write, whatever I wrote is not easy to understand, so i would appreciate forum...

Hello! (Wave) A $m \times m$ grid is a graph of which the vertices are ordered pairs of natural numbers $(n_1, n_2)$ with $1 \leq n_1 \leq m$ and $1 \leq n_2 \leq m$. Two vertices $(k_1,k_2)$ and $(k_3,k_4)$ are neighbors iff $|k_1-k_2|+|k_3-k_4|=1$. We suppose that a unique number $y_w$ is...

Hey all, we're making a robot that teaches itself to walk using a genetic algorithm(took a hiatus with this but have returned). So i coded a simulator that to see why the GA wasn't working well with realistic physics. The GA works like this "A++,B---,D+" would mean motor A's angle increase by...

##A,B## are symmetric matrices of graphs ##G,H## respectively. For ##x \in G##,consider the graph ##(G-x)##, it has vertices adjacent to ##x## and vertices non adjacent to ##x##.## A_x## is the symmetric matrix of the graph ##(G-x)##, where ##C## is the symmetric matrix of the graph created by...

So I've been writing an algorithm to build a function tree and I believe I'm aaaaallllllmost there. The intent is to take a math function like x^2+x+1*5 and build it into / + \ / + \ / \ / ^ \ x 1 * 5 x 2...

Hello everyone, I have been interested in trajectory optimization for a while now and I have read a few papers on that topic and bought the book "Spacecraft trajectory optimization" from Cambridge University Press and want to start programming with the goal to optimize a trajectory in a...

I know from the Fourier Analysis that any signal can be represented as summation of elementary signals i.e. basis functions .Likewise,any image can be represented as summation of Basis images. Is there any available code, or even an algorithm, that would allow me to compute Basis images of an...

Hello! (Wave) I want to write an algorithm that finds an optimal vertex cover of a tree in linear time $O(n)$, where $n$ is the number of the vertices of the tree.. A vertex cover of a graph $G=(V,E)$ is a subset $W$ of $V$ such that for every edge $(a,b)$ in $E$, a is in $W$ or $b$ is in...

Hey all, writing this simple genetic algorithm but its not working. Any idea why? static int len = 30; static char[,] dog = new char[len, 30]; static void breed() { sort(); int Ii0 = r.Next(0,15); int Ii1=r.Next(0,15)...

Hello! (Wave) Give an algorithm that finds the MST (maximum spanning tree) of a graph $G=(V,E)$. Prove that the algorithm you gave finds the MST. I tried the following: I applied the Kruskal algorithm, but instead of ordering the edges by weights in increasing order I ordered them in...

Hello! (Wave) Steps to build Huffman Tree Input is array of unique characters along with their frequency of occurrences and output is Huffman Tree. 1. Create a leaf node for each unique character and build a min heap of all leaf nodes (Min Heap is used as a priority queue. The value of...

Hello! (Wave) I am asked to write a $Ο (n \lg k)$ - time algorithm that merges $k$ sorted lists into one sorted list, where $n$ is the the total number of elements in all the input lists. Hint: Use a thin heap for a $k$ -way merging. Do you have an idea what could be meant with thin heap ...

I am not sure whether this question should go in Quantum Physics, Computers, or Linear Algebra. I am willing to see it moved if appropriate. In Nielsen and Chuang's "Quantum Computation and Quantum Information", in explaining quantum parallelism in section 1.4.2 (as a preparation for Deutsch's...

Hey! :o Which of the following sorting algorithms are (or can be implemented as) stable: Insertion Sort, Merge Sort, Heap Sort, Quicksort ?? How can we determine it?? (Wondering)

I am not sure whether it should be here, or in statistical mathematics or in computers thread...feel free to move it. I am using it here because I am trying to understand the algorithm when it's used in particle physics (e.g. identification of neutral pions in ATLAS). As I read it: In general...

I have come across this Proportional Integral- Derivative( PID) control theory. I feel that it is highly beneficial and accurate. I want to create a new algorithm which is more accurate, faster, efficient than PID. Also it should be easily programmable in microcontroller. So what are the...

Hey all, I'm currently working on an app that requires the a sub routine to extract 'blob"s from images, ie if I have multiple black shapes on a white background split them into separate images. Google turned up nothing, my soultion was to 1. flood fill pixel(0,0) with color[0] 2.add color to...

I'm going through an explanation in a number theory book about Tonelli's algorithm to find the square roots of a quadratic residue modulo ##p## where ##p## is prime, i.e. I want to solve ##x^2 \equiv a \pmod{p}## with ##(\frac{a}{p}) = 1##. The book goes as follows: Let ##p - 1 = 2^s t##, where...

Hi, I am working on TDR (Time Domain Reflectometry). I send a 7GHz bandwidth fast rising edge (14ns) square wave into a coax. I get a return Signal. I have an ADC with 10Msamples/sec. I am using MPLAB IDE for coding the microcontroller. Now I would like to increase the Points on the...

Hi, I am new to world of electronics and to high frequency Domain. But I am working on a design where I have a coax of 30cm length. I have used an external oscillator to generate 7GHz fast falling pulse. I am using a Controller to control the oscillator. Now I have a pulse of about 350ns...

The N-R (iterative) formula is: xi+1=xi - f(xi) / f '(xi). A textbook exercise states that the N-R method does not converge for an initial guess of x >~ 1. I wrote the required program for tanh and found the method diverges at x >~ 1.0886. But I don't understand why it is this value - the N-R...

Hi all, I'm busy writing my first genetic algorithm. A simple one that finds an expression to give a desired number, ie you'll give it the number 40 and it will give you 5*7+5. I have the fitness function, the parser that uses the string to compute the number and the crossover system, so only...

Hello. I`m looking for help to write the coorect PID algorithm for heating controller. For start in attachment I`m sending You the graph. If someone of You can help I could send some more informations.Greg.

Homework Statement Consider a strictly decreasing function F: ℕ → ℤ. We want to find the "first place where f is at or below the horizontal axis." Assume we can compute ƒ(i) for any input i in constant time. Clearly, we can solve the problem in O(n) time by evaluating ƒ(1), ƒ(2), ƒ(3)...

Hello! (Wave) Consider a singly-linked list L each element of which is a struct with two fields, an integer num and a pointer next to the next element of the list. Describe an algorithm that gets as argument a pointer to the first element of the list L and that creates a new list L' that...

Hi! (Smile) Could you give me a difficult exercise that is related to the Dijkstra's algorithm? (Blush)

Homework Statement Not actually for homework, but i didn't know where to post this. Problem: Show that any integer to the fourth power can be expressed as either 5k or 5k+1 where k is an integer. Homework Equations None. The Attempt at a Solution My starting point is to consider that all...

In my computational physics textbook, three different velocity estimators are derived for a problem with equation of motion: \ddot x = F(x) where the positions are found by using the Verlet algorithm: x(t+h) = 2 x(t) - x(t-h) + h^2 F[x(t)] The three velocity estimators are: v(t) = \frac{x(t+h)...

Homework Statement The minimum number of comparisons required to find the minimum and the maximum of 100 numbers is ... Homework Equations ##T(n)=T(\lceil \frac{n}{2} \rceil) + T(\lfloor \frac{n}{2} \rfloor) + 2## The Attempt at a Solution Recurrence for the above problem is ##T(n)=T(\lceil...

How to do this? Show the step by step how the following data is sorted into ascending order using the given sorting algorithm : 22 85 43 28 65 35 i) Selection sort. ii) Insertion Sort.

In Dijkstra's algorithm (for an efficient way to find the shortest path between two given vertices, or nodes, in a graph), the only freedom the programmer has is to name which of the two given vertices one begins with. Is there any efficient way to tell which one of the two one should start...

Hey! :o Let the quicksort algorithm be the following: procedure QUICKSORT(S) if S contains at no one element then return S else begin choose an element a randomly from S; let S1, S2 and S3 be the sequences of elements in S less than...

Hi! (Smile) I am looking at the following exercise: Let $M=\{ y_1, y_2, \dots, y_n \}$ a set of real numbers, where $n \geq 2$. Describe an algorithm, that has time complexity $o(n^2)$ and that finds and returns two elements $y_k$ and $y_l$ of $M$, such that: $$|y_k-y_l|=\min_{1 \leq i,j \leq...

Hi! (Nerd) This is the algorithm of Quicksort , according to my notes: Quicksort(A,p,r) if (p>=r) return; q=Partition(A,p,r); swap(A[q],A[r]); Quicksort(A,p,q-1); Quicksort(A,q+1,r) Partition(A,p,r) x=A[r]; i=p-1; for (j=p; j<r; j++){ if (A[j]<=x){...

Hello! (Nerd) We are given the following algorithm: 1.BUILDHEAP(A) 2. for (i=floor(size(A))/2; i>=0; i--) 3. HEAPIFY(A,i); according to my notes, we could prove its correctness, proving the following sentence: At the beginning of each iteration of the for loop at the lines...

Hello! (Mmm) I am looking at the following algorithm: MERGESORT(A,l,r){ if (R==L) return; MERGESORT(A,l,floor((r+l)/2)); MERGESORT(A,floor((r+l)/2)+1,r); return MERGE(A,l,r,floor((r+l)/2)); What does the above algorithm do? Could you explain it to me? (Thinking)