What is Tree: Definition and 312 Discussions

In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only wood plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. Trees tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are some three trillion mature trees in the world.A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier. Below the ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development.
Trees usually reproduce using seeds. Flowers and fruit may be present, but some trees, such as conifers, instead have pollen cones and seed cones. Palms, bananas, and bamboos also produce seeds, but tree ferns produce spores instead.
Trees play a significant role in reducing erosion and moderating the climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues. Trees and forests provide a habitat for many species of animals and plants. Tropical rainforests are among the most biodiverse habitats in the world. Trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In parts of the world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture. Because of their longevity and usefulness, trees have always been revered, with sacred groves in various cultures, and they play a role in many of the world's mythologies.

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  1. I

    Solve 3D Visit-Once Tree Puzzle with 16x16x16 Grid

    I'm trying to build a software function that explores a 3d grid visiting the cells just once. The file below is my last attempt, which misses some cells (for 16x16x16 it visits 3436 cells instead of 4095). Can anyone give me a reference to a solution, please.
  2. V

    Computing Minimum Spanning Tree in R: A Step-by-Step Guide

    Hi guys. Could you please give me more information regarding the necessary library and/or the code I should use to compute the Minimum Spanning Tree in R? Many thanks.
  3. R

    Unlocking the Energy Potential of Trees: A Look at Biomimicry

    A tree seed takes water and minerals(?) from the ground, carbon and oxygen(?) from the air, and heat and light(?) from the sun. When a tree dies and dries up, it can be used as firewood, a source of energy. Is there a way to capture that energy without the seed-tree scenario? i.e., but can we...
  4. G

    Safety Essay on Fault Tree Analysis

    Hi All, would someone (hopefully a professional), who has used Fault Tree Analysis read my essay and give me some pointers for improvement? I'd really appreciate if someone could help, especially since this is the only essay I've written in recent years.
  5. Imager

    LaTeX Learn How to Draw a Christmas Tree with Latex | Stack Exchange

    I was looking for something else at Stack Exchange and found a how to draw a Christmas tree with Latex thread. I thought the one by Loop Space was the best! http://tex.stackexchange.com/questions/39149/how-can-we-draw-a-christmas-tree-with-decorations-using-tikz
  6. Greg Bernhardt

    C7 xmas lights too hot for tree?

    My wife likes the old school bulb look so I picked up some C7 string lights for the tree. This year we got a real tree. I plugged the light string in and after a few minutes the bulbs got so hot I couldn't touch them. Are these things really that safe and ok to put around a tree? I must imagine...
  7. L

    MHB Prim's algorithm for minimal spanning tree

    Quite stuck on this how do i do this and how do i document each step?
  8. mooncrater

    Different Node Deletion/Insertion in a Binary Search Tree

    What happens, if instead of having any pointer pointing to a node's parent, we had pointer pointing to the node's successor? We know, that Searching would remain the same. But in my opinion Insertion and Deletion would change. This would happen, because in insertion, we would be needed to find...
  9. mooncrater

    I Asymptotics for finding the successors in a Binary Tree

    Consider the algorithms : TREE-SUCCESSOR(x) 1. if x.right_child !=NIL 2. return TREE-MINIMUM(x.right_child) 3. y=x.parent 4. while y != NIL and x == y.right_child 5. x = y 6. y = y.parent 7. return y TREE-MINIMUM(x) 1. while x.left_child != NIL 2. x = x.left_child...
  10. FallArk

    Create a binary search tree in python with the support of variables

    My instructor asked us to create a binary search tree in python that supports variables. i.e. the tree will have variables inside, and the user can get the values for those variables by looking for the name of that variable. I don't really know how to implement this. What I have so far: class...
  11. S

    Djikstra's algorithm with distance 1 between every node

    Does anyone know whether there exists a specialized Djikstra's algorithm for when every node has the same distance between it? Or to think of it another way, an algorithm for simply finding the minimum number of moves to get from 1 node to another? e.g. in the following A - B - C...
  12. T

    MHB Stuck with probability question involving tree diagram?

    Dear friends, I'm unable to solve the following probability question. Please help me solve it. Thanks in advance. The answer given in the book is: 5/9 [for part (b)]. Don't know even if the answer is correct. Suzi has taken up golf, and she buys a golf bag containing five different clubs...
  13. A

    Force applied on cable attached to car and tree

    Homework Statement your car is stuck in the mud and you can’t pull hard enough to get it out. You do, however, have a long cable that you connect taut between your front bumper and the trunk of a stout tree. You now pull sideways on the cable at its midpoint, exerting a force f. Each half of...
  14. C

    Proof about min spanning tree property

    Homework Statement (a) If e is part of some MST of G, then it must be a lightest edge in some cutset of G. Homework Equations Cut property The Attempt at a Solution When the cutset has just one edge then yes it's true obviously. I am think I can do this by contradiction. Assuming e_i is part...
  15. Z

    Do we have stack involvement in a threaded tree?

    Homework Statement In the book it gives following background for using threaded trees: "The concern is that some additional time has to be spent to maintain the stack & some more space has to be set aside for the stack itself." & then it says "It is more efficient to incorporate the stack as...
  16. I

    A Can a Tree Visit Every Cell in a Cubic Lattice Blindly?

    I need to generate a tree in a cubic lattice that, from any cell, visits every other cell in the lattice just once. This visit must be blind, that is, it is not allowed to mark the cell as visited. Thanks in advance for any solution or reference.
  17. chwala

    Differential equation tree height

    1. Homework Statement A tree is planted as a seedling of negligible height. The rate of increase of its height , in metres per year is given by ##0.2√(25-h)## a. explain why tree can't exceed 25 metres. answer⇒ ##dh/dt=0## when h=25 b. express t as a function of h answer⇒...
  18. Edison Bias

    How Do Trees Absorb Nutrients and Survive Winter?

    Hello all you folks! This question might not be the most advanced in universe yet I wonder. How does a tree for instance suck up water and nutricians from the ground? And why does it get rid of all the leaves in the winter (if it is not a pine tree that is)? Does it get rid of all the leaves...
  19. ChrisVer

    Problem with creating a Tree from another+histogram

    Suppose I have a histogram : h(x) and I want to take the different values h(x_i) as weights which I can pass in a tree... The code I wrote so far, which (theoriticially) would do this job for me looks like this: TFile* fin = new TFile("file_contains_tree_and_histo.root"); TH1F* h_x = (TH1F*)...
  20. G

    How can the countability of binary trees be proven?

    Homework Statement We'll define a binary tree as a tree where the degree of every internal node is exactly 3. Show that the set of all binary trees is countable. Homework Equations A set is countable if it is finite or there is a one-to-one correspondence with the natural numbers. The Attempt...
  21. M

    Probability - Tree Diagram problem

    Please delete this, I made a mistake with the problem and textbook.
  22. domainwhale

    Insights High Temperature Low Temperature Duality for the Ising Model on an Infinite Regular Tree - Comments

    domainwhale submitted a new PF Insights post High Temperature Low Temperature Duality for the Ising Model on an Infinite Regular Tree Continue reading the Original PF Insights Post.
  23. Dennydont

    How Do Clocks on Moving Trains Behave Near a Tree?

    Homework Statement Two trains of proper length L move toward each other in opposite directions on parallel tracks. They both move at speed v with respect to the ground. Both trains have clocks at the front and back, and these clocks are synchronized as usual in the frame of the train they are...
  24. G

    Data structures and algorithms: Priority queue as Binary Tree

    Homework Statement Explain and compare two efficient implementations of a priority queue using binary tree. Ilustrate this on an example of ascending priority queue that is created when elements 15, 38, 45, 21, 8, 55,20 are inserted and the two largest elements are deleted. Homework Equations...
  25. barbara

    MHB Postorder Tree Traversal: Calculating the Result

    The following algorithm describes a postorder tree traversal Postorder(tree) If left subtree exists then Postorder(left subtree) If right subtree exists then Postorder(right subtree) Print root end How can I apply that to the following tree...
  26. wololo

    Tree Data Structures & Minimax Algorithm for Games

    Homework Statement Homework Equations Tree data structures. I think it might also have something to do with minimax algorithm, but it was only mentioned once and never discussed extensively in class so I doubt it is required. The Attempt at a Solution [/B] If both players play as well as...
  27. TheMathNoob

    Algorithm to find the minimum spanning tree on a planar graph

    Homework Statement I have the following algorithms: Prime MST with array, Prime MST with priorityq and Kruskal with priorityq. I have to choose the best algorithm to find the minimum spanning tree on a planar graph. A planar graph has the property in which the number of edges is in O(number of...
  28. ckirmser

    Can a Christmas Tree have evenly spaced lights with no leftover string?

    Got a question: I've got a Christmas tree that needs lights strung on it, but I want to know how to hang the lights so that the entire string is spaced evenly and it ends at the top with nothing left over. I figure there's a formula to derive this, but I don't know what it may be. Any...
  29. H

    Vacuum diagrams vs. tree diagrams vs. loop diagrams

    Could someone please tell me the difference between tree diagrams and loop diagrams? If I'm thinking correctly tree diagrams are before contracting? Also how do vacuum diagrams fit into the picture? Thanks!
  30. W

    Can I throw a Banana Peel Next to a (City?) Tree ?

    So I was done eating a banana while in the sidewalk, and had the peel on my hand. Instead of throwing it in the trash, I thought I would break it into pieces and throw the pieces into a small , planted area surrounding a tree, both contained within a metal encasing, so that the peel would...
  31. G

    Calculating Tree Amplitude for Spin J Exchange

    I am wondering something about the tree amplitude for exchange of a spin J resonance-- the basic calculation that exhibits the famous regge behavior. I see that one way to do the calculation is simply to note that the 4-point function for spin J exchange amongst massless particles arises from an...
  32. C

    Year 1 physics: Fluid Dynamics with Tree Sap replacing Water

    Homework Statement A tree loses water to the air by the process of transpiration at the rate of 110 g/h. This water is replaced by the upward flow of sap through vessels in the trunk. If the trunk contains 1900 vessels, each 100 μm in diameter, what is the upward speed of the sap in each...
  33. D

    Binary search tree, number of nodes formula

    Homework Statement Hello! Typical binary search tree has a number of nodes equal to 2^(n+1) - 1. I don't understand why we add 1 to the n? For example: a tree has a height 4. # # # # # # # # # # # # # # # each level has 2^i nodes; i = 0, 2^0...
  34. S

    Prime Implicants of a Non-Coherent Fault Tree

    I am stuck on some non-coherent fault tree analysis. I have a non-coherent fault tree for which the TOP event breaks down to TOP = AD' + DA' + A'E. These are (I think) some of the prime implicants of the fault tree. There is also another prime implicant ED'. I've been trying to work through it...
  35. H

    What Causes the Crooked Growth of Trees on the Saskatchewan Hillside?

    When a tree grows even at an angle on a hill side it mostly remains vertical . What is at play here to cause the vertical direction of growth ? Thank you, Pat Hagar
  36. S

    Can a decision tree algorithm minimize wastage for given volumes?

    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...
  37. J

    Having trouble with algorithm to build a function tree

    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...
  38. B

    Statics problem: man lowering himself from tree w/ friction

    Homework Statement The 180-lb tree surgeon lowers himself with the rope over a horizontal limb of the tree. If the coefficient of friction between the rope and the limb is 0.60, compute the force (P) which the man must exert on the rope to let himself down slowly. Homework Equations T1/T2...
  39. N

    What is the pressure inside that tree?

    Hi, Having a background of horticulture training (NZTCH) and tree specialisation (NSW Arbor Techniques & Tree Surgery), I'm very interested in biomechanics so enjoy books written by authors like Prof. Dr. Claus Mattheck http://www.mattheck.de/english/english2.htm My question is: Given a height...
  40. N

    What pressure inside that tree trunk?

    Hi, Having a background of horticulture training (NZTCH) and tree specialisation (NSW Arbor Techniques & Tree Surgery), I'm very interested in biomechanics so enjoy books written by authors like Prof. Dr. Claus Mattheck http://www.mattheck.de/english/english2.htm No idea what forum area this is...
  41. W

    Is it a good idea to fire a shotgun against a tree?

    Homework Statement [/B] When Danny was 13, he went deer hunting with his grandfather. He decided that he didn't like the "kick" of the gun, so he pressed himself against a tree before firing a 12-gauge (3.5kg) loaded with a deer slug (0.22kg). Evaluate this idea. It was a big mistake. It...
  42. phyzguy

    Dead Tree Full of Acorns: What's Placing Them There?

    While we were hiking in California, we came upon this dead tree. The tree was full of holes, presumably made by woodpeckers, and in most of the holes something had placed an acorn. Has anyone ever seen this? What places the acorns there? Woodpeckers? Squirrels? Something else?
  43. evinda

    MHB Drawing a 2-3 Tree & Inserting/Deleting Keys

    Hello! (Wave) Assume that at the nodes of a 2-3 tree, the following keys are saved (in an increasing order): $3,6,9,15,18,21,24, 27, 30, 33, 36$. It is also given that the root is a 2-node that contains the number $12$.Draw the tree. PS: It is not required to make so many insertions as the...
  44. evinda

    MHB Deleting Element from 2-3 Tree Example

    Hello! (Wave) I am looking at the deletion of an element of a 2-3 tree. If the key that we want to delete (let $K$ ) is contained in a leaf, we delete it. Otherwise, the key (let $K'$) that is the next of $K$ in the in-order traversal is contained in a leaf, so we replace $K$ with $K'$ and...
  45. evinda

    MHB Constructing a Decision Tree: Explained!

    Hello! (Wave) In my notes there is the following decision tree: Could you explain me how it is constructed? (Thinking)
  46. M

    How long has the tree been dead?

    Homework Statement A tree contains a known percentage p0 of a radioactive substance with half-life tau. When the tree dies the substance decays and isn't replaced. If the percentage of the substance in the fossilized remains of such a tree is found to be p1, how long has the tree been dead...
  47. 22990atinesh

    How to check whether an array represents max heap

    Homework Statement Does the following array represents the binary max heap 99,98,97,55,49,49,48,13,54 99,98,97,55,54,49,49,48,13 Homework EquationsThe Attempt at a Solution I've tried to construct the tree structure and all the above array representation satisfies the binary max heap property...
  48. evinda

    MHB Finding the $j^{th}$ Smallest Element in an AVL Tree

    Hello! (Wave) We consider an $\text{ AVL }$ tree $T$. At each node $v$ of the tree the number of nodes of the left subtree of $v$ is stored. I want to write an algorithm that returns the $j^{th}$ smallest element of the tree in time $O(\log m)$ where $m$ is the number of nodes of the tree. How...
  49. M

    MHB A decision tree has an expected depth of at least log n

    Hey! :o I am looking at the proof of the following theorem and I have some questions. The theorem is the following: The proof is the following: Let $D(T)$ be the sum of the depths of the leaves of a binary rtee $T$. Let $D(m)$ be the smallest value of $D(T)$ taken over all binary trees $T$...
  50. evinda

    MHB Exploring the Cost of a Recursion Tree

    Hi! (Wave) According to my notes: $$T(n)=T\left(\frac{n}{2} \right)+T\left(\frac{n}{4} \right)+T\left(\frac{n}{8} \right)+n$$ Th recursion tree is this: https://www.physicsforums.com/attachments/3626 Cost per level $i \to \left( \frac{7}{8} \right)^{i-1}n, i \geq 1$ Leaf per level $i \to...
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