Does anyone know how to retrieve parameters from a formula column in a data table?
I'm using the nonlinear platform to estimate parameters for a custom equation. I want to retrieve some of those parameters so I can use them to add reference lines to a graph. How do I get the params into my script?
I've been trying to use "Get Formula", which returns the formula itself in a variable. But while it looks like a character string, it isn't. So I can't interrogate it using something like "Contains" (which gives an error).
Here's what doesn't work:
names default to here(1);
clear log();
dt=current data table();
a=column("Ypred")<<GET formula=""></GET>
Output looks like this:
a = Parameter({x2 = 43.392460252954, x3 = 99.9985293436864, b1 = 0.217052884609186, tau0 = 6.8300208159237, b2 = 13.6749994042758, b3 = 2.0025718816485, xoffset2 = 79.8284250939869, b4 = 158.586185051408, tau2 = 12.9572197347909, x1 = -0.0000000143754505748, xoffset1 = 13.8700526412164, b0 = 0.731036046206343}, If(:x < x1, b0 * (:x < x1), :x < x2, b1 * Exp((:x - xoffset1) / tau0) * (:x >= x1 & :x < x2), :x < x3, (b2 + b3 * (:x - x2)) * (:x >= x2 & :x < x3), b4 * (1 - Exp(-((:x - xoffset2) / tau2))) * (:x >= x3)));
expecting integer in access or evaluation of 'x2' , "x2" /*###*/
at line 11 in Script for Example 2
Hi Jerry,
It looks like JMP is trying to evaluate a, which it cannot, as it does not know about all the parameters in the expression (due to scoping). The NameExpr( ) function will prevent this... see if the following works:
contains(char(nameexpr(a)), "x2");
Cheers,
Brady
Good thought, but (sadly) same error as before Brady.
