Main.SlackVariables History

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June 18, 2013, at 12:04 AM by 69.169.131.173 -
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 ! Example model with slack variable
 ! Solve slack variable problem
 !   Minimize     total_cost
 !   Subject to   supply < b
 Model
  Parameters
    b = 5
  End Parameters

  Variables
    supply
    total_cost
  End Variables

  Equations
    supply < b

    total_cost = (supply-2)^2

    Minimize  total_cost
  End Equations
 End Model

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June 17, 2013, at 11:58 PM by 69.169.131.173 -
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Example Problem

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Example Problem

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Inequality Constraints in APM

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Inequality Constraints in APM

June 17, 2013, at 11:58 PM by 69.169.131.173 -
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June 17, 2013, at 11:57 PM by 69.169.131.173 -
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June 17, 2013, at 11:56 PM by 69.169.131.173 -
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Example Problem

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Example Problem

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Inequality Constraints in APM

June 17, 2013, at 11:55 PM by 69.169.131.173 -
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June 17, 2013, at 11:54 PM by 69.169.131.173 -
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Click to Solve a Slack Variable Optimization Problem
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In APMonitor, inequality constraints are automatically translated into equality constraints with slack variables. Slack variables can also be defined by starting a variable name with slk. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

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Click to Solve a Slack Variable Optimization Problem
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In APMonitor Modeling Language, inequality constraints are automatically translated into equality constraints with slack variables. Slack variables can also be defined by starting a variable name with slk. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

June 17, 2013, at 11:52 PM by 69.169.131.173 -
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Slack variables are defined to transform an inequality expression into an equality expression with an added slack variable. The slack variable is defined by setting a lower bound of zero (>=0).

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Slack variables are defined to transform an inequality expression into an equality expression with an added slack variable. The slack variable is defined by setting a lower bound of zero (>0).

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slack >= 0

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slack > 0

June 16, 2013, at 05:34 PM by 69.169.188.188 -
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In APMonitor, slack variables can be defined by starting a variable name with slk. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

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(:html:) <iframe width="560" height="315" src="http://www.youtube.com/embed/jh6BK0BqqIs?rel=0" frameborder="0" allowfullscreen></iframe> (:htmlend:)

In APMonitor, inequality constraints are automatically translated into equality constraints with slack variables. Slack variables can also be defined by starting a variable name with slk. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

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March 16, 2012, at 03:27 PM by 69.169.136.170 -
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Solve Slack Variable Optimization Problems
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Click to Solve a Slack Variable Optimization Problem
March 16, 2012, at 03:26 PM by 69.169.136.170 -
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(:title Slack Variable Tutorial:) (:keywords slack variables, inequality, slacks, lower bound, transform:) (:description Slack variables are used to transform an inequality expression into an equality expression:)

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January 14, 2012, at 04:30 PM by 69.169.188.228 -
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Solve Slack Variable Optimization Problems
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Solve Slack Variable Problems Online

APMonitor has an online interface for solving optimization problems. The optimization problem shown below as Example Problem can be solved through the web-interface at the following link:

Slack Variable Solution Online
January 14, 2012, at 04:26 PM by 69.169.188.228 -
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x = b + slack

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x = b + slack (:html:)<br>(:htmlend:)

January 14, 2012, at 04:24 PM by 69.169.188.228 -
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x = b + slack,

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x = b + slack

January 14, 2012, at 04:23 PM by 69.169.188.228 -
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x = b + slack

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x = b + slack,

January 14, 2012, at 04:23 PM by 69.169.188.228 -
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January 14, 2012, at 04:20 PM by 69.169.188.228 -
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In APMonitor, slack variables can be defined by starting a variable name with slk. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

to:

In APMonitor, slack variables can be defined by starting a variable name with slk. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

January 14, 2012, at 04:20 PM by 69.169.188.228 -
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In APMonitor, slack variables can be defined by starting a variable name with 'slk'. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

to:

In APMonitor, slack variables can be defined by starting a variable name with slk. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

January 14, 2012, at 04:19 PM by 69.169.188.228 -
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January 14, 2012, at 04:19 PM by 69.169.188.228 -
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January 14, 2012, at 04:18 PM by 69.169.188.228 -
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January 14, 2012, at 04:18 PM by 69.169.188.228 -
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January 14, 2012, at 04:16 PM by 69.169.188.228 -
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Slack variables are defined by starting a variable name with 'slk'. Thus, valid slack variable names would include names such as slk_1, slkr, slkvar[1]. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero.

Equation inequalities are automatically tranformed to equality expressions for solvers that do not support them.

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(:table border=1 width=50% align=left bgcolor=#EEEEEE cellspacing=0:) (:cellnr:) Inequality Constraint Form (:cell:) x > b (:cellnr:) Equality Constraint Form with Slack Variable (:cell:) x = b + slack slack >= 0 (:tableend:)

In APMonitor, slack variables can be defined by starting a variable name with 'slk'. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero. Alternatively, inequality constraints will be automatically converted to equality constraints with a slack variable.

July 20, 2011, at 04:41 AM by 89.147.0.172 -
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 ! Example model with slack variable declaration
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 ! Example model with slack variable
July 20, 2011, at 04:31 AM by 89.147.0.172 -
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 Model example
   Parameters
     p1 = 5
   End Parameters

   Variables
     slk_variable
     v1 < 4
   End Variables

   Equations
     v1 = p1 - slk_variable
   End Equations
to:
 ! Solve slack variable problem
 !   Minimize     total_cost
 !   Subject to   supply < b
 Model
  Parameters
    b = 5
  End Parameters

  Variables
    supply
    total_cost
  End Variables

  Equations
    supply < b

    total_cost = (supply-2)^2

    Minimize  total_cost
  End Equations
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 Solution
  p1 = 5
  slk_variable = 1
  v1 = 4
to:
July 20, 2011, at 04:02 AM by 89.147.0.172 -
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Slack variables are defined to transform a inequality expression into an equality expression with an added slack variable. The slack variable is defined by setting a lower bound of zero (>=0).

to:

Slack variables are defined to transform an inequality expression into an equality expression with an added slack variable. The slack variable is defined by setting a lower bound of zero (>=0).

July 20, 2011, at 02:37 AM by 89.147.0.175 -
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APMonitor has an online interface for solving optimization problems. The optimization problem shown below can be solved through the web-interface at the following link:

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APMonitor has an online interface for solving optimization problems. The optimization problem shown below as Example Problem can be solved through the web-interface at the following link:

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Example

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Example Problem

July 20, 2011, at 02:36 AM by 89.147.0.175 -
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Attach: table50.jpg Slack Variable Solution Online

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Slack Variable Solution Online
July 20, 2011, at 02:35 AM by 89.147.0.175 -
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Slack Variable Solution Online

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Attach: table50.jpg Slack Variable Solution Online

July 20, 2011, at 02:31 AM by 89.147.0.175 -
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APMonitor has an online interface for solving optimization problems. The optimization problem shown below can be solved the web-interface at the following link:

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APMonitor has an online interface for solving optimization problems. The optimization problem shown below can be solved through the web-interface at the following link:

July 20, 2011, at 02:29 AM by 89.147.0.175 -
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Solve Slack Variable Problems Online

APMonitor has an online interface for solving optimization problems. The optimization problem shown below can be solved the web-interface at the following link:

Slack Variable Solution Online

July 07, 2009, at 09:10 AM by 158.35.225.228 -
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Slack variables are defined to give slack for infeasibilities. Generally, a slack variable is used to turn off an equation in a region where it does not apply. The slack variable is defined by setting a lower bound of zero (>=0) and including the variable in the objective function.

Slack variables are defined by starting a variable name with 'slk'. Thus, valid slack variable names would include names such as slk_1, slkr, slkvar[1]. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero and included in the objective function.

to:

Slack variables are defined to transform a inequality expression into an equality expression with an added slack variable. The slack variable is defined by setting a lower bound of zero (>=0).

Slack variables are defined by starting a variable name with 'slk'. Thus, valid slack variable names would include names such as slk_1, slkr, slkvar[1]. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero.

Equation inequalities are automatically tranformed to equality expressions for solvers that do not support them.

September 25, 2008, at 01:24 PM by 158.35.225.230 -
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Slack Variables

Slack variables are defined to give slack for infeasibilities. Generally, a slack variable is used to turn off an equation in a region where it does not apply. The slack variable is defined by setting a lower bound of zero (>=0) and including the variable in the objective function.

Slack variables are defined by starting a variable name with 'slk'. Thus, valid slack variable names would include names such as slk_1, slkr, slkvar[1]. When the model is parsed at run-time, any variable beginning with slk is automatically assigned a lower value of zero and included in the objective function.

Example

(:table border=1 width=50% align=left bgcolor=#EEEEEE cellspacing=0:) (:cellnr:)

 ! Example model with slack variable declaration
 Model example
   Parameters
     p1 = 5
   End Parameters

   Variables
     slk_variable
     v1 < 4
   End Variables

   Equations
     v1 = p1 - slk_variable
   End Equations
 End Model

(:cellnr:)

 Solution
  p1 = 5
  slk_variable = 1
  v1 = 4

(:tableend:)