5 if the elements in a column (ROW) of a determining factor are the sum of two numbers, they can be split into two forms of the addition of the two determining factors.
Property 6: multiply the elements of a column (ROW) of the determinant by the same multiple and add them to the elements corresponding to the other column (ROW). The determinant remains unchanged.
PS: generalized lower Triangle Matrix
PS: use the property to convert the determinant into the top triangle, so as to calculate th
Review... Copy linear algebra and Its Application
Linear Equations
1. Similar
X_1-2x_2 =-1
-X_1 + 3x_2 = 3
There are three situations
1. No solution 2. There is a unique solution 3. There is an infinite Solution
Consider two parallel lines, the intersection line, and the exact coincidence line. Solving Equations
Primary Line Transformation (Multiplier, swap, multiply) Two Problems of Linear Equations
1. Is there at least one solution?
1. Introduction to relational algebraRelational algebra is an abstract query language and a traditional expression of relational data manipulation language. It expresses queries by relational operations. The calculation object of relational algebra is relational, and the calculation result is also relational 2. relational algebra (1 ). A set operation is generall
Directory
Linear Algebra
I. Basic Knowledge
Ii. vector operations
Iii. Matrix Operations
Linear Algebra 1. Basic Knowledge
All vectors in this book are in the form of column vectors:\ [\ Mathbf {\ VEC x} = (x_1, x_2, \ cdots, X_n) ^ t = \ begin {bmatrix} X_1 \ X_2 \ vdots \ x_n \ end {bmatrix} \] all the moments in this book \ (\ mathbf x \ In \ mathbb R ^ {M \ times n }\) are:\ [\ Mathbf
Mastering linear algebra in 10 days: astoundin
Translator: mapleflying
Recently, my friend Scott Young made an amazing feat: within a year, he completed all 33 of the legendary mit computer science curriculum, from Linear Algebra to Computational Theory. The most important thing is that he is self-taught. He watches online tutorial lectures and uses actual tests for self-evaluation. (Go to Scott's FAQ pag
Tags: filter example row storage Dremel processing Speed font statement classificationA few graphs to read the column-type storageThe parallel execution of SQL queries is derived from Dremel and Impala , so we take this opportunity to learn more about relational databases and the parallel computation of relational algebra . speedup and scaleup Speedup refers to using twice times the hardware for half of the execution time .Scaleup refers to twice t
be extracted by an array named key;The Savetxt (), Loadtxt () function can read and write a text file that holds a one-dimensional and two-dimensional array, outputs the text separated by the spacer, specifies the spacer by the delimiter parameter, and the default output is in the form of '%.18e ', separated by a space by default.4. Memory-mapped arraysCreates a memory-mapped array from a file that reads the specified offset data,> without reading the entire file into memory by Memmap ():FileNa
transformed in order to find a suitable linear combination(linear combination) that makes AX = bThe corresponding diagramVector b is a sum of two col vectorsHere again, when Vector x is taken, we can get the entire XY plane, meaning that whatever vector B can find the corresponding solution(not when two col vectors are parallel)* The practice of column picture does not seem to be emphasized in schools, but this understanding is more useful for mastering matrices and vectorsThen the teacher exte
Inverse of ab,a^ (a transpose)Product of elimination matrices A=lu (no row exchanges)Inverse of ab,a^ (transpose of a):Product of elimination matrices A=lu (no row exchanges)E32e31e21a=u (no row exchanges) Ea=uA=e21 ' E31 ' E32 ' UL represents the lower triangular matrix, lower triangleD represents a diagonal matrix, diagonal triangleA=luL=e21 ' E31 ' E32 'Compare Ea=u A=lu, which form is better?ExampleSet E31 as the unit matrix,The A=lu form is more concise, if no row exchanges, multipliers go
[Question 2014a05](1) set \ (x_1, x_2 \ cdots, X_n, X \) to all uncertain elements. \ (S_k = X_1 ^ K + x_2 ^ K + \ cdots + x_n ^ k \, (K \ geq 1) \), \ (s_0 = n \), try to find the value of the following determinant:
\ [| A | =\begin {vmatrix} s_0 S_1 \ cdots S _ {n-1} 1 \ S_1 S_2 \ cdots s_n X \\\ vdots \ vdots \ s_n S _ {n + 1} \ cdots S _ {2n-1} x ^ n \ end {vmatrix }. \]
(2) set \ (A = (A _ {IJ}) \) to \ (n \) square matrix, and try to find the value of the following determinant
Ultraviolet A 10655-contemplation! Algebra
Question Link
Meaning: Given P, Q, N representsP=A+B,Q=ABPleaseAN+BN
Train of Thought: the rapid power of the matrix. The formula is transformed to get (AN+BN)(A+B) =AN+ 1 +BN+ 1 +AB(AN? 1 +BN? 1), move the item to getAN+ 1 +BN+ 1 = (AN+BN)P?Q(AN? 1 +BN? 1)
In this way, you can use the Matrix to quickly calculate the power.
Code:
#include
[Linear algebra] returns the number of reverse orders.
1 # Include 2 Using Namespace STD; 3 // Returns the number of reverse orders. 4 // By default, the standard sequence in descending order is: from small to large. 5 Class Reversed_order 6 {7 Public : 8 Void Num ( Int Newn ); 9 Private : 10 Int Array_num [ 11 ], Temp, numb, result; 11 }; 12 Void Reversed_order: num (Int Newn) 13 { 14 Temp = newn; 15 // Store each digi
Recursive formulas are obtained by calculationThe direct recursion calculation should time out (not try), the better method is to convert to a matrix and then use the matrix to optimize the power quickly.That is, N>=1,Also, be aware of the end of the input, "input is Terminatedby a line containing only two zeroes. ”1#include 2#include 3#include 4#include 5#include 6#include string>7#include 8#include 9#include Set>Ten#include One#include A using namespacestd; - #defineIOS Ios_base::sync_with_
, R=m because all rows have a main element, after the elimination of a total of 0 rows, the ax=b has an infinite number of solutions.and the number of free variables is n-r, and the 0 space of matrix A is not only 0 vectors.Like what:watermark/2/text/ahr0cdovl2jsb2cuy3nkbi5uzxqvdgvuz3dlaxr3/font/5a6l5l2t/fontsize/400/fill/i0jbqkfcma==/ Dissolve/70/gravity/center ">3, R=m=n. That is, columns, rows are full rank (matrix reversible)Because the columns and rows are full rank, there are some properti
1. The Calculate the variance of a certain set of data: Pts_mean = SUM (nba_stats["pts"])/len (nba_stats[' pts ')point_variance = 0For I in nba_stats[' pts ']:difference = (i-pts_mean) * * 2Point_variance + = DifferencePoint_variance = Point_variance/len (nba_stats[' pts ')2. Something to the power have the highest pirority, then mutiply and Devide, the Add and subsract.3. Raise to the 11 fifth power. Assign the result to e . ( 11**5)Take the fourth root of 10000 . (10000** (1/4))4. Use STD ()
] ["Median_income"].mean () for _ in range (+)] # Get the mean of randomly 1 XX numberPlt.hist (Random_sample, 20)Plt.show ()7. If we would like to does some calculations between the sample columns, we can do it like this: def select_random_sample (count):# This function was to get "count" number of sample from the data setRandom_indices = random.sample (range (0, income.shape[0]), count)return Income.iloc[random_indices]Random.seed (1)Mean_ratios = []For I in range (£): # loopSample = Select_r
!Problem Description A sequence Sn is defined as:
Where A, B, N, M is positive integers.┌x┐is the ceil of X. For example,┌3.14┐=4. You is to calculate Sn.You, a top coder, Say:so easy!
Input There is several test cases, each test case in one line contains four positive integers:a, B, N, M. Where 0Output for each of the case, output an integer Sn.Sample Input2 3 1 20132 3 2 20132 2 1 2013Sample Output4144The question asks for the answer, and we find (A-1) ^2(a+sqrt (b)) ^n+ (a-sqrt (b
1. The machine-level program treats the memory as a very large byte array called virtual memory . Each byte of the memory is identified by a unique number, called its address , and the collection of all possible addresses is called virtual address space . This is just a conceptual image that is presented to the machine. The actual implementation is to combine RAM, disk storage, special hardware, and operating system software to provide a seemingly uniform array of bytes to the program.2, the low
Mymathlib and the computing experience.PNS) Ab=e, then a A, a, a and a inverse of the inverse of the a,a is equal to the determinant value of the inverse of the determinant is worth reciprocal; The inverse of the inverse B of the product of AB multiplied by the inverse of A; A reversible, a transpose inverse equals inversion of the transpose;38) Special matrix: All matrices, quantity matrix, diagonal matrix, quasi-diagonal matrix, upper triangular matrix, lower triangular matrix, symmetric matr
necessary and sufficient condition to prove its existence is \ (| g_k|\) coprime, the full use of the cycle group has just been discussed proof \ (a\) decomposition of each factor is its generation of the elements of the group, the necessity is through the construction of two \ (p-\) Order (refer to the next article) of the product to export contradictions. In addition, if \ (G=g_1\times g_2\) and \ (G_1\leqslant h\), it is easy to prove that there is \ (H=g_1\times (G_2\cap H) \).\[h= (H\cap g
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