First, the common object operation: In addition to the usual function keys of the general windows window. 1, !dir can view the files of the current working directory. !dir& can be viewed in the dos state. 2, who can view the current workspace variable name, whos can view the variable name details. 3. Function keys: Function key shortcut description Direction key Ctrl+P returns the previous line input Direction down key Ctrl+N to return to the next line of input Left arrow Ctrl+B cursor moves backward one character Right arrow Ctrl+F cursor moves forward one character Ctrl+directional right Ctrl+R cursor moves one character to the right Ctrl+direction left key Ctrl+L cursor moves one character to the left Home Ctrl+A cursor moves to the beginning of the line End Ctrl+E cursor moves to the end of the line Esc Ctrl+U clears a line Del Ctrl+D Clears the character where the cursor is located Backspace Ctrl+H Delete the previous character of the cursor Ctrl+K Delete to the end of the line Ctrl+C interrupts the command being executed 4, clc can command the contents of the window display, but does not clear the workspace. Second, the function and operation 1, the operator: +: plus, -: minus, *: multiplication, /: except, \: left division ^: power, ': complex conjugate transpose, (): make the order of operations. 2, commonly used function table: Sin( ) sine (variable is radians) Cot( ) cotangent (variable is radians) Sind( ) sine (variable is degree) Cotd( ) cotangent (variable is degree) Asin( ) arcsine (return radians) Acot( ) inverse cotangent (return radians) Asind( ) arcsine (return degree) Acotd( ) anti-cotangent (return degree) Cos( ) cosine (variable is radians) Exp( ) index Cosd( ) cosine (variable is degree) Log( ) logarithm Acos( ) residual sine (return radians) Log10( ) takes the base 10 logarithm Acosd( ) residual sine (return degree) Sqrt( ) Tan( ) tangent (variable is radians) Realsqrt( ) returns a non-negative root Tand( ) tangent (variable is degree) Abs( ) takes the absolute value Atan( ) arc tangent (return radians) Angle( ) returns the phase angle of the complex number Atand( ) arctangent (return degree) Mod(x,y) returns the remainder of x/y Sum( ) vector element summation 3. The rest of the functions can be obtained with the help elfun and help specfun commands. 4, the value of commonly used constants: Pi 3.1415926....... Realmin minimum floating point number, 2^-1022 i imaginary unit Realmax maximum floating point number, (2-eps) 2^1022 j imaginary unit Inf no limit Eps floating point relative longitude = 2^-52 NaN null Third, arrays and matrices: 1, the method of constructing an array: incremental and linspace (first, last, num) first and last for the start and end number, num is the number of array elements needed. 2, the method of constructing the matrix: you can directly use [ ] to input the array, you can also use the function provided below to generate the matrix. Ones( ) creates a matrix with all elements of 1 in which dimensions, 1, 2, ... variables can be formulated Zeros() creates a matrix with all elements 0 Eye() creates a matrix with a diagonal element of 1 and other elements of 0 Diag() creates a diagonal matrix from the vector, that is, the elements of the vector are diagonal elements Magic() creates a cube matrix Rand() creates a random matrix subject to uniform distribution Randn() creates a random matrix that obeys a normal distribution Randerm() creates a random row vector Horcat C=[A,B], horizontal aggregation matrix, can also use cat(1,A,B) Vercat C=[A;B], vertical aggregation matrix, can also use cat(2,A,B) Repmat(M,v,h) aggregates the matrix M v times in the vertical direction and aggregates h times in the horizontal direction Blkdiag(A,B) Create block diagonal matrices with A, and B as blocks Length returns the length of the longest dimension of the matrix Ndims returns the dimension Numel returns the number of matrix elements Size returns the length of each dimension, [rows,cols]=size(A) Reshape Reshapes the matrix, reshape(A, 2,6), and transforms A into a 2×6 matrix, arranged in columns. Rot90 rotation matrix 90 degrees, counterclockwise Fliplr flips the matrix along the vertical axis Flipud flip matrix along horizontal axis Transpose flips the matrix along the main diagonal Ctranspose transpose matrix, can also use A' or A.', which is only when the matrix is ​​a complex matrix Inverse of the inv matrix Determinant value of the det matrix The sum of the diagonal elements of the trace matrix Norm norm of a matrix or vector, norm(a,1), norm(a,Inf)....... Normest estimates the maximum norm vector of the matrix Cholesky decomposition of chol matrix Cholinc incomplete cholesky decomposition Lu LU decomposition Luinc incomplete LU decomposition Qr orthogonal decomposition Kron(A,B) A is m×n, and B is p×q, then a matrix of mp×nq is generated. Each element of A is multiplied by B and occupies a space of p×q size. Rank to find the thorn of the matrix Pinv pseudo-inverse matrix A^p operates on A A.^P operates on each element in A Fourth, numerical calculation 1. Solving linear equations (1) The solution of AX=B can be obtained by X=A\B. The solution of XA=B can be obtained by X=A/B. If A is a matrix of m × n, a unique solution can be found when m = n, m (2) AX=b, A=L×U, [L,U]=lu(A), X=U\(L\b), which is solved by LU decomposition. (3) QR (orthogonal) decomposition is a product of a matrix represented by an orthogonal matrix and an upper triangular matrix, A = Q × R [Q, R] = chol (A), X = Q \ (U \ b) (4) cholesky decomposition is similar. 2, the characteristic value D=eig(A) returns a matrix of all the eigenvalues ​​of A. [V, D] = eig (A), also returns the feature vector matrix. 3. A=U×S×UT, [U, S]=schur(A). The diagonal element of S is the characteristic value of A. 4. The polynomial in the polynomial Matlab is represented by a vector. The specific operation functions are as follows: Multiplication of conv polynomials Deconv polynomial division, [a,b]=deconv(s), return quotient and remainder Poly Find the coefficient of the polynomial (the coefficient of the polynomial from the known root) Polyeig finds the eigenvalue of a polynomial Polyfit (x, y, n) Polynomial curve fit, x, y is the fitted vector, and n is the fitted polynomial order. Polyder finds the first derivative of a polynomial, polyder(a,b) returns the derivative of ab [a,b]=polyder(a,b) returns the derivative of a/b. Polyint polynomial integral Polyval finds the value of a polynomial Polyvalm finds the value of a polynomial with a matrix as a variable Residue partial fraction expansion Roots finds the root of the polynomial (returns the vector of all roots) Note: Use the feature(A) to find the characteristic polynomial of the matrix, and then find the root, which is the eigenvalue of the matrix. 5. The commonly used interpolation functions for interpolation are as follows: Griddata data grid blend surface fitting Griddata3 3D data grid hybrid hypersurface fitting Interp1 one-dimensional interpolation (yi=interp1(x,y,xi,'method')Method=nearest/linear/spline/pchip/cubic Interp2 two-dimensional interpolation zi=interp1(x,y,z,xi,yi'method'),bilinear Interp3 3D interpolation Interpft performs one-dimensional interpolation with fast Fourier transform, help fft. Mkpp uses piecewise polynomial Spline cubic spline interpolation Pchip piecewise hermit interpolation 6, the solution of the function's maximum value Fminbnd('f',x1,x2,optiset(,)) finds the minimum value of f between x1 and x2. The Optiset option can have 'Display' + 'iter' / 'off' / 'final', which means that the calculation process is displayed / not displayed / only the last result is displayed. Fminsearch finds the minimum of a multivariate function. Fzero('f',x1) finds the zero of the unary function. X1 is the starting point. The same options as above can be used. Fifth, image drawing: 1, the basic drawing function Plot drawing a two-dimensional linear graph and two axes Plot3 draws a three-dimensional linear graph and two axes Fplot draws an image of a function in the development interval. Fplot('f', region, line type, color) Loglog draws a logarithmic graph and two axes (both coordinates are logarithmic) semilogx draws a semi-logarithmic coordinate graph Semilogy plotting semi-logarithmic coordinates 2, line type: color line type y yellow. dot line v down arrow g green -. combination > right arrow b blue + point is plus sign < left arrow m red purple o hollow round p pentagram c blue purple* asterisk h hex star w white. solid dot hold on add graphics r red x fork shape grid on add grid k black s square - solid line d diamond -- dashed line ^ up arrow 3. Subplot (3, 3, 1) can be used to divide the drawing area into three rows and three columns, and the first region is currently used. At this point, if you want to draw different graphics in a window, you need to hold on. High Speed Edge Sealing Machine High Speed Edge Sealing Machine,Woven Bag Small Sealing Machine,Household Woven Bag Sealing Machine,Fully Automatic Woven Bag Sealing Machine Dongguan Yuantong Technology Co., Ltd. , https://www.ytbagmachine.com