Constants are ignored when a function is supplied to a `fitter` as a callable

[julian-wolf]

When a model function is supplied to a fitter instance as a string, everything works as expected. Supplying an actual callable function, though, results in constants being ignored (all arguments are treated as parameters). The inspect module has some metaprogramming stuff that might be helpful in finding a fix—namely, getargspec plus some substitution and a lambda could probably be made to do something useful.

[jayich]

Having the ability to input functions as well as strings sounds like a nice improvement. inspect is part of the standard library, which is good.

@jaxankey , what do you think?

[julian-wolf]

The functionality for using callables already (mostly) exists; see https://github.com/Spinmob/spinmob/blob/master/_data.py#L1236-L1242

The issue is that, when this is how functions are supplied, they don't seem to "fix" any parameters, even those listed as constants.

[jayich]

Right. Looks like a bug, not an enhancement.

This docstring says it can be a function:
https://github.com/Spinmob/spinmob/blob/master/_data.py#L1142-L1146

[jaxankey]

There is no easy way to make the callables work with constants, because it means you have to redefine the callable; that would add a level of complexity that is not necessary, especially since it's not needed. I am thinking of removing the ability to supply callables, because you can always just supply something like this: fitter('f(x)', g=dict(f=my_callable)) xoxoxo Jack

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On Sat, Feb 4, 2017 at 8:04 PM, jayich ***@***.***> wrote: Right. Looks like more of a bug that needs to be fixed. This docstring says it can be a function: https://github.com/Spinmob/spinmob/blob/master/_data.py#L1142-L1146 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#87 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AH5Fp9haT0lkZ8VaFzz_DAhCHj41F76Eks5rZSAfgaJpZM4L2-GG> .

[julian-wolf]

That's a good work-around; hadn't thought of that. Rather than disallowing supplying callables all together why not just change

self.f.append(f[n])
self._fnames.append(f[n].__name__)

to something along the lines of

self._globals[f[n].__name__] = f[n]
self.f.append(eval('lambda ' + pstring + ': {}(x)'.format(f[n].__name__), self._globals))
self._fnames.append(f[n].__name__)

at https://github.com/Spinmob/spinmob/blob/master/_data.py#L1241-L1242? Would that fix the constants issue?

(I haven't tested this)

[jaxankey]

The goal being to convert the callable into a string function at the outset? That could work. Test it :)

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-Jack Sent from sender's phone with typos. Sender not liable for inflammatory autocorrects. On Feb 5, 2017 11:27 PM, "Julian Wolf" <notifications@github.com> wrote: That's a good work-around; hadn't thought of that. Rather than disallowing supplying callables all together why not just change self.f.append(f[n])self._fnames.append(f[n].__name__) to something along the lines of self._globals[f[n].__name__] = f[n]self.f.append(eval('lambda ' + pstring + ': {}(x)'.format(f[n].__name__), self._globals))self._fnames.append(f[n].__name__) at https://github.com/Spinmob/spinmob/blob/master/_data.py#L1241-L1242? Would that fix the constants issue? (I haven't tested this) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#87 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AH5Fp2v5zYfjGWPTU_nAkHfsr_2rxBTJks5rZqEdgaJpZM4L2-GG> .