Re: vpasolve to find all real roots for multiple nonlinear equations and multiple variables

[Oliver Heimlich]

Am 30. Mai 2016 17:45:37 MESZ, schrieb sam kjm <address@hidden>:
>Thanks for pointing that out!
>
>My updated codes are as follows:
>## Constant parameters
>k0 = 0.1; #uM/min
>kd = 0.05; #/min
>k1 = 0.6; #uM/min
>j1 = 0.1; #uM
>km1 = 0.2; #uM/min
>jm1 = 0.1; #uM
>k2 = 0.4; #/min 
>j2 = 0.1;#uM
>km3 = 7.05;# /min
>jm3 = 2; #uM
>
>
>
>## setting the variables prot1 and prot2s
>total_prot2 = 2; # total protein2 in the cell
>syms prot1 prot2s positive; #prot2s = activated protein2
>prot2 = total_prot2 - prot2s; # prot2 = unactivated protein2 
>
>
>
>## setting the rate expressions (degradation rate, production rate etc)
>v0 = k0;
>v1 = vpa((k1 * prot2) / (j1 + prot2));       
>vm1 = vpa((km1 * prot2s) / (jm1 + prot2s));        
>v2 = vpa((k2 * prot1 * prot2s) / (j2 + prot2s));         
>vm3 = vpa((km3 * prot1 * prot2s) / (jm3 + prot2s));
>
>
>
>## 2 steady state equations to be solved by vpasolve etc...
>ss_prot1 = v0 - v2 - kd*prot1 == 0;
>ss_prot2s = v1 - vm1 - vm3 == 0; 
>
>
>equations = [ss_prot1, ss_prot2];
>variables = [prot1, prot2s]; ## an update here prot2s
>[sol_prot1 sol_prot2] = vpasolve(equations, variables)
>
>
>
>And I got the following
>Python exception: TypeError: bad operand type for abs():
>'MutableDenseMatrix'
>    occurred at line 20 of the Python code block
>
>Is there probably another way to vpasolve? I tried fsolve before but it
>needs initial values so it gives me only 1 answer for prot1 and 1
>answer for
>prot2s for a particular start value for prot1 and prot2s
>
>
>
>
>
>--
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>http://octave.1599824.n4.nabble.com/vpasolve-to-find-all-real-roots-for-multiple-nonlinear-equations-and-multiple-variables-tp4677276p4677279.html
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>
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Did you look at fsolve of the interval package? It will compute a coverage of 
any solutions in the search range, e. g., in the range [0, 2] for each 
variable. There are several examples in the package documentation.

Oliver