Items tagged with population

How do we write code for optimal problem using Pontryagin's maximum principle for simulation.


I am working on making a population balance model for gas bubbles is a stirred reactor. I have data in excel about the bubble size and need to make a population model to compare the experiment with theoretical findings.

But I have not much experience in population balance modeling. Is there anyone who has an example of a solved population balance model in maple? This would help me greatly in understanding the subject. I would want to use the Luo and Svendsen model as I found it most matching with the result.

Kind regards, Hasselhof

Dear Maple experts,

I would like to generate population data that is the best possible approximation of a multivariate normal distribution with a specified covariance matrix and vector of means. I do not want to draw a sample from a multivariate distribution, but I want the population values itself which are approximately multivariate normal distributed. The size of the datamatrix should be limited, otherwise I could draw a huge sample from a multivariate normal distribution. For instance, I would like to generate a 200 by 6 data matrix that is the best (or at least good enough) approximation of a MVN distribution. For a bivariate normal distribution one could calculate the probalities of a grid by integrating the density, but for six variables that seems undoable. 

Before trying the invent the wheel again, I think I will ask this question to experts, because it is unlikely that there is no already existing algorithm that does the job pretty well.

Thanks in advance,

Harry Garst

I have no idea where to start with this problem.

I know how to create arrays, but I want to assign characteristics to each position in the array; the array being a population with each member having a set of characteistics like height, weight etc. I want to be able to have some of the characteristics able to change with time, and some remain constant (those that change with time will be defined by generic equations)

I have tried looking on maplesoft for answers, and the help within maple 16, but have been unable to make any progress.


Sorry if the question is not specific enough.


Thanks in advance x

Hi, I need help with graphing a certain logistics population model for an initial population size that is equal to 1.

dy/dt = k(1 - y/M)y  k=2 M(t)=10e^-t/5 +3(1-e^-t/5)

So far I've worked out the values to input, but I don't know how to write it in Maple.

I know all I have to replace is the M in the dy/dt equation with these 2 values.

M(0) = 10

M(t goes to infinity) = 3



I am trying to plot a Linear Population Model using Maple, could anybody tell me what I am doing wrong. My plot is just registering as a straight line at 1.0 and I know this is incorrect.


Hello everyone,

I have a problem with the Brownian Motion (I'm using Maple 15).

Here is the code:


X1:=SamplePath(X(t),t=0..T,timesteps =T/d):



The last line give me a number different from zero, which is not true for a Brownian Motion as defined.

Could you please tell me where is the problem?


PS: I have the same problem with WienerProcess(sigma).

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