Using a custom function to find fix points about pydstool HOT 8 CLOSED

On Tue, Jul 28, 2020 at 5:28 PM ulyssek ***@***.***> wrote: Hi there, And thanks for this amazing package. I'm using it to find phase plane for my system, but I'd like to use a custom function. Here's what I'm doing : ## imports from PyDSTool.Toolbox import phaseplane as pp import PyDSTool as dst ## Creating the Vode_ODEsystem params = { 'my_custom_function' : np.array([0,1,2]) ## Here's where I'm using a custom function, in the form of a numpy array } domains = { 'x' : [0,1], 'y' : [0,1], } functions = { 'foo' : (['z'], 'my_custom_function[int(2*z)]'), ## This line is not working } eqs = { 'x' : '-2 * x + foo(x)', 'y' : '- y', } DSargs = dst.args(name='my_model') DSargs.pars = params DSargs.fnspecs = functions DSargs.varspecs = eqs DSargs.tdomain = [0, 30] DSargs.xdomain = domains dmModel = dst.Vode_ODEsystem(DSargs) ## Finding the fix points pp.find_fixedpoints(dmModel, n=4, eps=1e-8) But this is not working, do you have any clue about what I could do here? Thanks a lot, — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#154>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABFEUZNKGJ4T7XVBI2ZQ36TR547H7ANCNFSM4PK6CJHA> .

On Wed, Jul 29, 2020 at 1:10 PM ulyssek ***@***.***> wrote: When I try this, I have the following error : TypeError: only size-1 arrays can be converted to Python scalars Obviously, Pydstool expect me to use scalars as parameters. Could you send me the link to the demo script? I couldn't find it in the doc. Thanks a lot — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#154 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABFEUZNQJ7KWYABILIG3Q6DR6BJZTANCNFSM4PK6CJHA> .

On Wed, Jul 29, 2020 at 4:34 PM Rob Clewley ***@***.***> wrote: Here you go. This is a hack to allow arbitrary code into your RHS, drawbacks being it is less structured and specific to the target language. E.g. if you wanted to run with Dopri or Radau, you'd have to re-implement the `foo` function in C. Note that you don't need numpy here at all. A python list literal takes care of what you need. ``` from PyDSTool.Toolbox import phaseplane as pp import PyDSTool as dst domains = { 'x' : [0,1], 'y' : [0,1], } eqs = { 'x' : '-2 * x + foo(x)', 'y' : '- y', } DSargs = dst.args(name='my_model') DSargs.vfcodeinsert_start = """ def foo(z): return [0,1,2][int(2*z)] """ DSargs.varspecs = eqs DSargs.ignorespecial = ['foo'] DSargs.tdomain = [0, 30] DSargs.xdomain = domains dmModel = dst.Vode_ODEsystem(DSargs) pp.find_fixedpoints(dmModel, n=4, eps=1e-8) ``` Note that the pre-processing of indented code's whitespace isn't great in vfcodeinsert, so all of those indentation spaces are needed to get it to parse. Alternatively, you could skip the function and replace the middle part of this with ``` eqs = { 'x' : '-2 * x + z', 'y' : '- y', } DSargs = dst.args(name='my_model') DSargs.vfcodeinsert_start = """ z = [0,1,2][int(2*x)] """ DSargs.varspecs = eqs DSargs.ignorespecial = ['z'] ``` On Wed, Jul 29, 2020 at 1:10 PM ulyssek ***@***.***> wrote: > When I try this, I have the following error : > > TypeError: only size-1 arrays can be converted to Python scalars > > Obviously, Pydstool expect me to use scalars as parameters. > > Could you send me the link to the demo script? I couldn't find it in the > doc. > > Thanks a lot > > — > You are receiving this because you commented. > Reply to this email directly, view it on GitHub > <#154 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/ABFEUZNQJ7KWYABILIG3Q6DR6BJZTANCNFSM4PK6CJHA> > . >