Tuesday, November 10, 2015

Mathematica: Linear Stability Analysis Symbolically

Trying to do a linear stability analysis of a 5 ODE system. Simple Egg -> Small Larvae -> Large Larvae -> Pupae-> Adult system (no delay and such) Assumptions 1) Recruitment into a class is same throughout all classes 2) There is larval competition between the small larvae and the large larvae (density dependent death- symbolized by mu1) 3) There is natural background mortality that is symbolized by mu0) This is just a symbolic analysis (not numerical). So I wrote down the differential equations. Equated the equations to 0. Then solved for the system using Solve in Mathematica I had three solutions. I ignored the first solution. Then I created a 5x5 Jacobian Matrix. I put in the solved equations into the Jacobian Matrix then found the eigenvalues. It seem that all the eigenvalues are negative and real (thus is stable)

Tuesday, November 3, 2015

HOST-PARASITOID- DELAY DIFFERENTIAL EQUATIONS WITH DISTRIBUTED DELAY

I swear I will write this all up and explain better. Notes: 1) Take with a grain of salt- still working on this 2) Parasitoid attack is based on a type II functional response 3) Converted DDEs into a system of ODES using the LINEAR CHAIN TRICK