Passing real function to a subroutine as argument

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1

Consider we have subroutine below that gets a real function as its first argument:

secant_bisection
secant_bisection3196Ɨ2604 386 KB

I have wrapped this subroutine in python using f2py.
The question is, How can we pass that real function to it in python?

2

Some other notes:

  • You should declare all the dummy arguments and other variables.

  • Also, do not use goto, but use a do loop.

I donā€™t know how f2py does it, or if it allows it.

1 Like
3

Are you looking to pass a python function as your f argument? If so, is this a callback issue? See https://numpy.org/devdocs/f2py/python-usage.html#call-back-arguments

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4

Yeah, thanks :pray: :pray:

5

I refactored subroutine above as follows:

callback error
callback error3196Ɨ2456 332 KB

and i tried to wrap it , but i got this error:

/tmp/tmp1rr3n3ta/src.linux-x86_64-3.7/sec_bimodule.c:335:56: error: ā€˜nofoptargsā€™ undeclared (first use in this function)
if (create_cb_arglist(f_capi,f_xa_capi,#maxnofargs#,#nofoptargs#,&f_nofargs,&f_args_capi,ā€œfailed in processing argument list for call-back f.ā€)) {
^
/tmp/tmp1rr3n3ta/src.linux-x86_64-3.7/sec_bimodule.c:356:22: warning: passing argument 1 of ā€˜f2py_funcā€™ makes pointer from integer without a cast [-Wint-conversion]
(*f2py_func)(f_cptr,&a,&b,&x_tol,&root);
^
/tmp/tmp1rr3n3ta/src.linux-x86_64-3.7/sec_bimodule.c:356:22: note: expected ā€˜float *ā€™ but argument is of type ā€˜intā€™

6

If f is a python function, you need to inform f2py that this is a intent(callback) argument in the .pyf file. This means the c pointer to the python function gets correctly assigned when wrapping. Is it possible for you to build a MWE and point me to it? I might be able to help via PR.

1 Like
7

I have created a separate callback branch: