How to plot agent variables in NetLogo - netlogo

I'm working through a textbook, and trying to plot the way a variable 'energy' changes over time, for two breeds, 'sheep' and 'wolves'.
When I try and plot the energy for wolves, I use the code:
plot [energy] of wolves
in the 'pen update commands' for my plot. When I try to run the model using the go procedure, I get the following error message:
PLOT expected input to be a number but got the list [105.09999999999982 129.59999999999982 112.09999999999982 112.09999999999982 112.09999999999982 108.59999999999982 129.59999999999982 115.59999999999982 108.59999999999982 119.09999999999982] instead.
error while observer running PLOT
called by plot 'Energy over Time' pen 'wolves' update code
called by procedure GO
called by Button 'go'
I'd appreciate it if anyone could tell me what I'm doing wrong, and how to get the plot to model the way the agents own variables change over time.

If you have 5 wolves, then you are asking NetLogo to plot a list of 5 numbers, but it needs a single number to plot (on y axis, and tick/time goes on x axis). You probably want the average energy of wolves. Try plot mean [energy] of wolves

Related

Dynamically replotting every tick

I'm trying to plot two turtle variables against each other in a scatterplot. I want this plot to update continuously, and erase the points from previous steps. I.e. I want one point to move to represent the variable values for one turtle throughout its lifetime, disappearing when it dies and these values equal zero.
This is my code for the pen update commands (isspecials is my turtle agentset)
ask isspecials [plotxy r invader-stride]
I tried adding
reset-plot-pens
to the end of it, but then nothing appears on the plot. I think it's almost as if I have to create a new pen for each turtle, but I can't tell. I'm really new to this, so if anyone has any suggestions I'd really appreciate it!
I tried adding
reset-plot-pens
to the end of it
Adding plot-pen-reset is the right idea! However, you need to add it before your plotting command.
The plot-pen-reset primitive erases everything that the plot pen has drawn. If you call it right after you plot, you don't get a change to see anything! Calling it just before plotting new stuff will ensure that the stuff you plotted in the previous tick has plenty of time to be seen.
Here is what you plot pen definition should look like:

Netlogo: plot update without adding new X axis values

So I'm doing a program where agents have a certain life value and I want to make a plot about it.
In the X axis is the ID of the agent.
In the Y axis is the life of the agent.
The problem I have is that in every tick of execution it creates a new X axis value and I only want to update Y values without adding X.
How can I do that?
While you should definitely check out Alan's suggestion, you can use plotxy to do what you're asking:
ask turtles [
plotxy id life
]
where id and life are the variables you want to use for x and y. That is, if you're just using who numbers as for your ids, you'd do plotxy who life. But yeah, do checkout Alan's suggestion.

MATLAB Plotting Contour Map from Different Plots

I am trying to write a MATLAB script to give me a contour map. The contour map must be created from inputs that I generated from 100 images.
The story is like this:
I have 100 images on which I ran an image processing algorithm for optimization. Now, I got their energy curves. So, I have 100 energy curves. I want to create a contour map that will show me where the points are denser on the plot. (the energy curves are plotted as energy vs. iteration with fixed number of iterations)
The following is my variable:
energy(iteration,numImages)
Hope I explained it well.
Thanks in advance.
I interpret your question to boil down to how can I create a surface plot with colors according to the energy found in energy. I would solve this by using the contour function with a grid generated using meshgrid. If each image is described in 1000 data points with 100 files the plot can be generated as follows:
% using stuff as random junk instead of energy
numPoints = 1000;
numFiles = 100;
stuff = rand(1000,100); % replace with actual information
[X, Y] = meshgrid(1:numFiles, 1:numPoints);
contour(X,Y,stuff);
You can also create a 3D surface plot using surf and the same logic.
From what i see of you graph (and using the comments also), one possible way is to use plot3 to plot a line in 3D for every plot.
For doing so, you can use something like this code:
x=(0:0.01:1)';
aexp=zeros(100,numel(x));
hold on
for ii=1:100;
% aexp(ii,:)=exp((-x+ii/10)); %exponential
aexp(ii,:)=exp(-(x-ii/100).^2); %~gaussian
% aexp(ii,:)= x*ii; %linear increase
plot3(x,aexp(ii,:),ii*ones(1,numel(x)));
end
% set(gca,'yscale','log'); % uncomment if you need logscale.
giving
I have a few options of plot. It always plot from the XY view. I changed by hand, but you can use the view command. Notice that i used a simple counter to make the spacing in the z direction.
In a similar manner, you can plot using the contour. For my code, after the data have been generated in the for loop, remove/comment the plot3 and add:
contour(aexp) %outside the for loop,
giving
Notice that i have not really take care what i'm plotting. You can find more info on contour in the Matlab page .
You commented that the x-axis should be number of iterations, y-axis should be energy and z-axis should be the information containing how many lines are passing through from some areas. For this, make a qq variable, being it qq=number_of_lines(number of iterations,energy) . Make a discrete grid for the energy if you don't have one. Number of iterations is probably discrete anyway. The function is you who need to devise, but i would go for something which checks the number of lines for every energy and every iteration. In this case you will have the z-function that depends on y and x, that is the case to use contour or surface.
My function above make a line for every ii point, to have a 3d function. An edition for another extra loop is not hard. Just remember to have the same regular grid for every point, otherwise you will have trouble.

Plotting variables of multiple agents

I am trying to plot a graph that shows the variables of all agents of one breed. Although the number of agents is rather small, I think there must be a more elegant way than creating a pen for every agent. Is there?
Elegance, here, depends on what exactly you want to do. It can be perfectly legitimate to create one plot pen per turtle, using create-temporary-plot-pen. Among advantages, it means that you can give each plot pen a name and show a legend on your plot.
That being said, it's also very easy to use a single pen for all your agents. Suppose you have multiple turtles, of different colors, and you want to plot their sizes. You can put something like this in a pen's "update commands":
ask turtles [ set-plot-pen-color color plotxy ticks size ]
This will change the pen to the color of each turtle and plot a single point for that turtle. Just be sure to set your pen to "point" mode in the advanced pen options.
Also notice the use of plotxy instead of just plot, allowing you to specify an x coordinate instead of relying on the "auto advance" behavior of plot.

Update some plots in NetLogo

Is it possible to have plots that are updated at different time points?
My model looks like that (it is replicator dynamics):
to go
repeat 10 [do-something]
replicate
tick
end
Then I would like to have one plot that is updated on tick, just like usual, and the second one that is updated at do-something and then reset at tick.
I tried to find a solution in documentation but update-plots command updates ALL plots which is not what i want.
You can use the various manual plotting commands (eg plotxy, plot-pen-down, plot-pen-up) to explicitly plot things, see the plotting section of the user manual, but is often simpler to have the plot commands in the plot rather than the code.
To do it in the plot instead of code, you could change to a structure like this (if your full code is suitable):
to go
do-something
if ticks mod 10 = 0 [ replicate ]
tick
end
and use the automatic update of plots with tick. You would also use the if ticks mod 10 = 0 trick in the update section of your plot.