Endsieg77's Studio.

matlab 0

2020/12/31 Share

Function:
exp(x): e^x

Commands:

who: show all variables
whos: who + types +values
clc: clear command window
clear: clear parameter table
format [parameter]
(parameter = short, long, shortE, longE, rational(rat))

  • Row vector
    >> a = [1 2 3 4]

  • Column vector
    >> b = [1; 2; 3; 4]

  • Matrix:
    >> c = [1 2 3; 4 5 6; 7 8 9]

Colon Operator

A = [1 2 3 ... 100]

j:k => [j, j+1, j+2, ..., j+m], j+m<=k
j:i:k => [j, j+i, j+2i, ..., j+m*i], j+m*i<=k

A(i,:) = [] clear the i-th row of A

arithmetic

point multiplication:.*

  • A = [a b; c d] B = [h i; j k]
  • A .* B = [a*h b*i; c*j d*k]

a an integer, a + A refers to the arithmetic that
each element of A plus a.
The ^ .^ / -follow the similar rule.

build some special matrixes

  • linspace(begin, end(, step(default value 1)))
  • eye(n): yields an n*n identity matrix.
  • zeros(n1,n2): yields a n1*n2 zero matrix.
  • ones(n1,n2): resembles zeros(). uses 1 instead.
  • diag([row_vector]): yields a diagnol matrix.
  • rand(): uniformly distributed random numbers.

Matrix functions

  • max(A): yields an row vector including the
    maximum num of each column of A.
  • max(max(A)): yields the maximum num of A.
  • min() sum() mean() resembles max() in terms of rules.
  • sort(): sort elements of each columns by ascending order.
  • sortrows(): sort rows with their first element by ascending order.
  • size(): yields two numbers representing the dimensional parameter.
  • length(): yields the multiplication of the two return value of size().
  • find(): e.g. A = [1 2 3; 4 5 6; 7 8 9], then find(4) = 2, find(8) = 6.
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