In the model, I need to time segments in which some agents go through, but not all, rendering the use of timeMeasureStart and End blocks ineffective as any agents who go through a certain End block MUST go through it's corresponding Start block, but not all agents that will encounter the End block will have gone through it's corresponding Start block.
I have done the following and receive the error that 'agent cannot be resolved to a variable' in the Histogram
Defined the variables startTime endTime cycleTime in the agent class Patient which is being pushed through the model.
Put agent.cycleTime=agent.endTime-agent.startTime; in the On enter slot of the block in which I want the timing to end.
Defined a Histogram Data called myDataSet with the Value agent.cycleTime in Main
Made a histogram in Main which takes myDataSet in it's Histogram slot.
First, you can still use TimeMeasureStart/end blocks. Just let some agents bypass them with a SelectOutput block upstream of the TimeMeasureStart block. The condition would be determined by who should be measured.
Ok, then to your details:
Put agent.cycleTime=agent.endTime-agent.startTime; in the On enter slot of the block in which I want the timing to end.
This is not how you would measure time. The variables are a good start, though. Do this instead:
Wherever timing should start, you write agent.startTime = time() (logs curr model time)
Wherever timing should end, you write agent.cycleTime = time() - agent.startTime, essentially measuring how much time has passed since the start.
Now you do what you want with agent.cycletime
Defined a Histogram Data called myDataSet with the Value agent.cycleTime in Main
this is not how you use Histogram Data. You need to use the API calls on it properly, for example myHistogramData.add(someValue):
Also, always check example models and the help, many issues can be solved by checking those first :)
Related
Currently, I have two delay blocks above each other, where one agent goes through one of the blocks and the other through the other one.
But when I want exponentially distributed values with a mean of 120 seconds, They both need to have the same value always. So they are done at the same time.
You simply need to have the two delay blocks use their own (but with the same seed) random object.
Start off by creating two identical random objects
And have each of the delay blocks use of them of them
Then the numbers they will sample will be the same for every sampling iteration.
See this post for a similar problem
Why do two flowcharts set up exactly the same end with different results every time the simulation is run even when I use a fixed seed?
Not questioning your probably bad design by not using resources, These are the steps to follow to ensure things happen at the exact same time:
1.Create a variable called seed of type long
2.create a cyclic event that runs every 1 minute and has the following code:
seed=(new Random()).nextLong();
3.In both blocks you will use the following code to calculate the exponential distribution:
exponential(120,0,new Random(seed))
I need to make a graph Y: Number of Agents out of Block, X: Waiting Time inside the queue of the Block.
The block is service. What is the method (if any) to get the time spent in the queue of the service block.
Or, if it is done by a function, or series of codes, can you write it step by step please, I am new to AnyLogic.
thanks...
Also, I need to make a graph of average waiting time of all process vs total time of event.
thanks.
If i got you right, you want to have a probability density function plotted as a bar chart. The standard way to do that would be to use HistogramData(HD) object to collect samples during simulation and then plot it.
Saving data samples to HD:
i suggest to create a variable in your agent to store the moment of time when agent entered the block, lets say you call it waitStart;
inside your service block put this code in "on enter":
agent.waitStart = time();
inside your service block put this code in "on enter delay":
yourHistogramData.add(time()-agent.waitStart);
And then you just plot your HD to the graph: right-click on you HistogramData and you will see "create chart".
As easy as that.
I have two Matlab function blocks that one is producing zero signal for the other. I want to store the exact time that signal changes to one in another parameter in order to use it elsewhere.
How can I do it?
This type of functinality is achieved using a Triggered Subsystem, as per the image below,
The output of the trigger block will take on value of the input (which in this case is the simulation time) every time the trigger signal rises. Look at the parameters of the Trigger block inside the subsystem for other options such as falling edge, or both edge, triggering.
Assume that you have a Simulink simulation where a certain signal is first positive and after some time t in a given interval, it becomes negative. Your goal is to find the zero-crossing.
A first approach would be to plot the signal over the given interval, save it and calculate the zero-crossing.
When repeating this simulation numerous times for varying parameters, it would be beneficial to be able to stop the simulation after the signal has become negative. Then there is already enough information for the calculation of the zero-crossing in Matlab. How could you do that?
Yes, use the Stop Simulation block with the appropriate logical input to the block:
You can use an if / else block to control the flow in the Simulink model. In the if / else block, you can choose the condition if u > 0, continue as normal if it's true, and use the else-option to bypass the rest of the flow you would otherwise run. For instance jump directly to the scope.
Another ways:
You can use Hit Crossing Block in Simulink to find time at the moment of hitting zero.
Another way - use any Trigger or Resettable system. It detects the zero crossing too. For example: this question at SO.
Of course you can also use User Defined function to detect zero crossing by your hand and do whatever you want with the signal at the same time.
About making a lot of simulations and then stops:
you can use Check Upper Static Bound for automatically stops simulation at the moment when zero will be crossed in nth time. For example:
I set upper bound = 10 for this block and this stops at 10th crossing.
There are a lot of ways to save function values in this points or just array of times but this is an another question :)
I have a matlab function block (which is not relevant) whose input is his previous output (loop). For example, if in a sample period the output is X, his input in the next sample period will be X, and so on.
This image shows a simplification of my simulation. I initialize the input of my function for the first loop.
The problem is that matlab functions recieves an event based signal from de initialization block in the first sample period (zero-duration), which I must convert to a timed based signal (so I can apply the unit delay that avoids an inifite loop, and allows to generate the next input as explained before). So, when I do so, I lose the information contained in the event-based signal (due to the zero-duration values) and the loop does not work.
If there was a way to intialize the loop in the time-based domain (green part of the image) so, in the first sample time, it is not a zero-duration signal, it would avoid the problem.
Is there any way to do so? Or, a different approach for this problem?
Two approaches come to mind
The initial condition can be set in the Unit Delay block, so it's not clear from your simplified example why you need the specific Initialization block.
You could just use a persistent variable inside the MATLAB Function block to maintain the state from one execution of the block to the next (noting that since it is event driven the block may not get called at every time step, only at each event triggger).