Linear programming problems statement of the problem: solution methods and formation

, , , , . — . (LP) . -. : , , .

Characteristics of linear programming tasks




LP:

  1. . , . , , , . , , .
  2. . , LP . , 1 , , . , LP . , .
  3. . — , , , , , . «Z».
  4. . LP . , , «b<3», b , . , / , .

Conditions task definition




, : , , , . LP , .





. LP, :

  1. , , , .
  2. : .
  3. . , , .
  4. : . , , , .
  5. : .
  6. : .

, . , .

, : X 1, X 2, X 3, ..., X n — ; C 1, C 2, C 3, ..., C n — .

:

  1. (≤). , , 2 .
  2. (=). , , .
  3. (≥). , , , .
  4. .
  5. LP .
  6. .

, .





Stages of setting objectives




:

  1. , .
  2. . n- .
  3. , .
  4. .
  5. , .

LP . , .

Graphical way




LP, , :

x ≥ 0, y ≥ 0, z ≥ 0 :

Ax + By + C z +. , ≤ N,

, , N .

«≤», «=» «≥».

LP :

  1. .
  2. .
  3. . LP.
  4. , , .

:

  1. , .
  2. .
  3. .
  4. , LP . , .

Sketching Solution Set




.

Gray area




, . :

  1. , .
  2. , (0,0). , .
  3. , — , . .
  4. , .
  5. , , , , , , .
Valid Area




-:

  1. , , , .
  2. .
  3. , , . . , . , , .
  4. . . «b» «a/b», "a" . , «b» .
  5. , , , , -, .
  6. , , , , , .
Simplex method to maximize




, -, , , . ( ) — , , .

LP (Ax + By +. , .≥ N) N, ( ). , , , . .

, , . , I .

I . . , , , . , , II.

II - . I - , .

Custom restrictions




, -.

PHPSimplex

LP . , .

PHPSimplex — - LP. . . , , , .

WanerMath:

Warneth 2 :

  1. ( ).
  2. .

, , . , . , «», , , , .

JSimplex — . LP . , . , «». , .

, .

LP

. 150 100 . 250 200 .

, 250 . — 20 , 50 . , .

:

  1. . , : x — , y — .
  2. , , : x ≥ 0, y ≥ 0.
  3. : x ≥ 150, y ≥ 100.
  4. - : x ≤ 250, y ≤ 200.
  5. 'x' 'y' - : + ≥ 250
  6. : P = -20x + 50y.
  7. : P = -20x + 50y , 150 ≤ x ≤ 250; 100 ≤ y ≤ 200; x + y ≥ 250.

Areas of use




:

  1. . , , , , .
  2. : , , . , , .
  3. : , , .
  4. , . , . .
  5. : , .
  6. : , .
  7. : , .

These are some of the most common applications where linear programming is used. In general, any optimization problem that satisfies the above conditions can be solved with its help.




All Articles