Matlab 常用命令记录

permute: Rearrange dimensions of N-D array

permute(A,order): “order” is the vector , and determines with the N-D array.

光源传递函数转换为光流场函数，是模糊的原理模型，由一个光源进行了扩散，导致模糊，可以是temperoal and spacial bluring, 可能需要分别进行分析，建模。

而对于雾产生的模型、雨滴、雪花等的模型还在研究中，有空再写。。。。

psf2otf()

PADARRAY: Pad array.

各种参数： B = PADARRAY(A,PADSIZE,PADVAL,DIRECTION) pads A in the direction specified by the string DIRECTION. DIRECTION can be one of the following strings.

常见的direction： String values for DIRECTION

‘pre’ Pads before the first array element along each dimension .

‘post’ Pads after the last array element along each dimension.

‘both’ Pads before the first array element and after the last array element along each dimension.

By default, DIRECTION is ‘both’.

rng - Control random number generation

nan - Not-a-Number

This MATLAB function returns the IEEE arithmetic representation for Not-a-Number (NaN).

N = NaN(n) is an n-by-n matrix of NaN values.产生了值为Nan的n*n的矩阵

randpermu: random permutation. This MATLAB function returns a row vector containing a random permutation of the integers from 1 to n inclusive.

p = randperm(n)

p = randperm(n,k)

用来随机产生n及其以内整数大小随机排列的k个整数行向量。

randi: Uniformly distributed pseudorandom integers（整数操作—）

randi(imax): 产生最大值为imax的标量

randi(imax,n）:产生一个n*n的矩阵，矩阵的值为[1 imax]区间的整数

randi(imax,sz1,sz2,…..)：产生一个大小为sz1*sz2*….的数组，数组的取值在[1 imax]区间

spdiags：Extract and create sparse band and diagonal matrices

dftmtx - Discrete Fourier transform matrix in Galois field

A discrete Fourier transform matrix is a complex matrix of values around the unit circle whose matrix product with a vector computes the discrete Fourier transform of the vector.

A = dftmtx(n) returns the n-by-n complex matrix, A, that, when multiplied into a length-n column vector, x, computes the discrete Fourier transform of x. In other words, y = A*x is the same as y = fft(x).

The inverse discrete Fourier transform matrix is

Ai = conj(dftmtx(n))/n

这种计算方法还是不错的~

GF: Create Galois field array(finite fields, i.e., fields with a finite number of elements)

fliplr: Flip array left to right

flipud: Flip array up to down