A: Let's add it to the dock as we go.
- Click on the desktop or the Finder icon on the dock so that you're talking to the Finder. There should be a "Go" menu at the top.
- Under "Go," choose "Applications."
- Find the folder called "Extend 6" and within it, find the application
called "Extend 6.0.4". The icon looks like this:
- Drag that application to the dock. The other icons will move around to make room for it.
- Close the Finder window(s)
Click once on the dock icon to launch Extend.
A:Libraries aren't opened when you first start the program; you have to do that. Click on Library > Open. This will open a file system browser. Select "Generic Lib." Notice that this is now added to the end of the "Library" menu. Repeat this procedure to open "Plotter Lib" and "Discrete Event Lib."
A: Control-Click on it and choose "select all segments." Then hit the delete key.
A: Use a holding tank and, in the dialog box, be sure to click the box that says "The 'want' connector can take tank negative" even if you aren't using the "want" connector. Apparently, the dialog really should say that the tank can go negative. That is, unless you check this box, you can't have a negative "InputIn." See:
(My thanks to Christina Willis for helping me figure this out.)
- Highlight the area where you want the frequency table to be. Typically, this is the column to the left of the column of bins. This should be one more than the number of bins, to make room for the "more" bin, which is all values larger than the largest bin value. (If any fall in there, you should probably use different bin values.)
- The values in the bins are the upper limit of the bin. So a bin value of 0.1 means all values less than or equal to 0.1.
- Then type the following formula, but don't press return. Use the
mouse to select the arrays or use a range formula.
=frequency( data-array, bins-array)
- Press cmd-return (alt-return on Windows). The formula will get distributed to all of the cells you highlighted. If you look at the formula, you'll see it has braces around it.
- Just as a double-check, total the frequency table. It should be the same as the number of data you have.
- You can then build a bar chart using the frequency table and the bins. This chart will automatically update if the data changes!
To do.
We'll use the frequency table idea from the previous question to do this.
- Set up your frequency table(s)
- Click on the chart icon or choose "Insert/Chart"
- Choose a bar chart (the default)
- Select your three columns of data for the data range
- Click on "Series in Columns"
- Click on the "series" tab
- Fill in the "Category (X) axis labels" using your bins
- click "finish"
To make it look better, you can control-click on a bar and choose "format data series." Then click on the "options" tab and set the "gap width" to 0
Here's an example:
This should help us find them. Note that this is not all the Extend blocks; it's just the ones that we have any familiarity with.
- Discrete Event Lib
- Activities
- Activity, Delay: this is the standard service block, we use this a lot
- Activity, Delay (attributes): a service block where the delay comes from an attribute, as with some of the more complicated service times.
- Activity, Multiple: this can serve multiple items at a time. It is used to cook multiple burgers in the Fast Food model.
- Attributes
- Get Attribute: Retrieves the value of an attribute. We use this a lot.
- Get Value: gets the value of the "value" attribute, which is the multiplicity of an item
- Set Attribute: Sets the value of an attribute. We use this a lot.
- Set Attribute(5): Sets several attributes (up to 5) using one block
- Set Value: sets the value of the "value" attribute, which is the multiplicity of an item
- Batching
- Batch: Allows items from several sources to be joined as a single item. We used this in the fast food model to join customers with their cooked burgers.
- Unbatch: Produces several items from a single input item.
- Generators
- Generator: Produces items at specified interarrival times. We use this a lot
- Information
- Count Items: counts the items that pass through it
- Status: displays the status of another block's output. Winton uses this a lot to compute, for example, interarrival times.
- Timer: displays the time that it takes an item to pass between two parts of a model. We use this a lot.
- Queues
- Queue, FIFO: A first-in, first-out queue
- Resources
- Resource: holds and provides items from a fixed collection. Used in the Fast Food Model to model the frozen burgers.
- Routing
- Activity, Service: passes an item only when the demand connector is connected and certain conditions exist. This is used in the Fast Food model to allocate a burger (resource) to each burger order (item).
- Combine: Combines the items from two different streams. Used to create loops in Winton's CPU model, among other models
- Exit: allows an item to leave the simulation. We use this a lot
- Exit (4): A four-input exit. You can count how many exited from each input and also the total.
- Select DE output: Allows a value to determine which of two routes an item takes. We use this to choose the shorter queues for an item.
- Statistics
- Executive: We always use this block in a Discrete Event model
- Activities
- Generic Lib
- Arrays: we don't use this
- Decisions:
- Decision: an "if" block that compares to values and produces a Yes or No. We use this a lot.
- Holding
- Accumulate: sums up its inputs
- Holding tank: sums up its inputs, optionally spreading them over a time unit and optionally adding at the beginning versus the end of a time unit
- Retain: holds onto a value for a time. We used this to compare a current value with a previous value in some coin-flip models.
- Inputs/Outputs
- constant
- input random number
- system variable. This allows you to select from a menu of system variables, such as "current time," which could be days or years or whatever your simulation is based on, or "current step" which could be. We use this to determine the denominator for some of our "law of large numbers" simulations or anything where we want to asymptotically approach some value.
- Timeout: this generates "pulses" (true or false) at given times, or even given time intervals. This is how the doors are closed in the "untimed" simulation, where we close the doors after 8 hours but serve customers that arrived before the doors closed.
- Interprocess Communication: we don't use this
- Math: these are mostly self-explanatory
- add
- conversion function
- conversion table
- divide
- equation
- Optimization: we don't use this
- Statistics
- Mean & Variance: we use this to compute summary stats for lots of values.
- Plotter Lib
- Histogram: counts the number of data or runs that fall into different numerical ranges. Default is 10 bins, with the sizes determined by the minimum and maximum value. You will usually want to customize these, particularly if any data fall outside any bins. The block will tell you if any data are missing from the histogram.
- Plotter I/O: plots the data from a process simulation. By default it adjusts the x and y ranges to the data, which is usually fine. You can plot up to 4 kinds of data. You can have different ranges, one for the left vertical axis and one for the right. You can control which vertical axis some input is plotted against in the "Trace properties" window, which is the icon all the way to the left at the top of the Plotter I/O window. You can also take logs of the data, using the "LN" icon. "Open Dialog" (the next icon) allows you to show (or not) the plot at the end of each run.
- Plotter, Multisim: plots one input for up to four runs. That is, if you run the simulation four times, it'll show that one input for the last four runs. It you run the simulation more times, it'll show the most recent four runs.
- Plotter, Discrete Event: plots data from a discrete-event simulation, otherwise very similar to Plotter I/O.
- Plotter, DE Multisim: plots data from discrete-event simulations, otherwise very similar to Plotter Multisim.
- Utilities Lib. More on this later.
It's the waiting time for the item that most recently left the block. Here's a model that demonstrates this:
This is a web page of models we know and the lectures they appear in.
