Hi,
I'm making some (slow) progress with Maxima, trying to work through some
textbook examples. The following produces a nice vector-field plot:
load(plotdf);
(r : 0.5, c : 0.01, e : 0.02, d : 0.1);
eq1: n1 * (r - c * n2);
eq2: n2 * (e * c * n1 - d);
plotdf([eq1, eq2], [n1, n2], [n1, 0, 1200], [n2, 0, 100]);
However, following examples don't work, and I don't know why not. They
do generate vector fields, but they indicate that n2 is always at
equilibrium, which is at odds with my hand calculations:
(theta : 1000, c : 0.01, a : 1, E : 0.0005, Z : 0.001);
eq1: theta - a * c * n1 * n2;
eq2: E * a * c * n1 * n2 - Z * n2;
plotdf([eq1, eq2], [n1, n2], [n1, 0, 4000], [n2, 0, 4000]);
(r : 1.1, c : 0.01, a : 1, e : 0.0005, s : 0.001);
eq1 : r * n1 - a * c * n1 * n2;
eq2 : e * a * c * n1 * n2 - s * n2;
plotdf([eq1, eq2], [n1, n2], [n1, 0, 100], [n2, 0, 100]);
So, have I screwed up the math or the code here?
Thanks,
Tyler
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