# What's the required format for multi-sample spike output in SpikeFitter of brian2 modelfitting

**URL:** <https://brian.discourse.group/t/whats-the-required-format-for-multi-sample-spike-output-in-spikefitter-of-brian2-modelfitting/662>\
**Category:** Support\
**Created:** [20 April 2022 03:57 UTC](https://brian.discourse.group/t/whats-the-required-format-for-multi-sample-spike-output-in-spikefitter-of-brian2-modelfitting/662 "2022-04-20T03:57:54Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![luckyeric320](https://yyz2.discourse-cdn.com/free1/user_avatar/brian.discourse.group/luckyeric320/32/390_2.png) [@luckyeric320](https://brian.discourse.group/u/luckyeric320)\
**Post date:** [20 April 2022 03:57 UTC](https://brian.discourse.group/t/whats-the-required-format-for-multi-sample-spike-output-in-spikefitter-of-brian2-modelfitting/662/1 "2022-04-20T03:57:54Z")

</div>

# Description of problem

I 'm trying to fit an aEIF model using the SpikeFitter class. The data used here consists of 5 traces of random current input and corresponding lists of spike times. Since the number of each output spikes given different input traces can’t agree I have to use a python dictionary for the output data, and the fitter fails to work. Still, the example given by the brian2modelfitting document ([Simple Examples — Brian2modelfitting 0.3 documentation](https://brian2modelfitting.readthedocs.io/en/stable/examples/base.html#spikefitter)) implies that it can tackle multi-sample fitting problem. I’m wondering what’s the data type and format of the ‘out\_spikes’ used in this given example. Thanks!

# Minimal code to reproduce problem

# What you have aready tried

# Expected output (if relevant)

# Actual output (if relevant)

# Full traceback of error (if relevant)

---

<div class="post-metadata">

**Author:** ![mstimberg](https://yyz2.discourse-cdn.com/free1/user_avatar/brian.discourse.group/mstimberg/32/11_2.png) [@mstimberg](https://brian.discourse.group/u/mstimberg)\
**Post date:** [21 April 2022 18:19 UTC](https://brian.discourse.group/t/whats-the-required-format-for-multi-sample-spike-output-in-spikefitter-of-brian2-modelfitting/662/2 "2022-04-21T18:19:20Z")

</div>

Hi @luckyeric320 I will have to look into this in more detail next week, but if I remember correctly, you can give a list of arrays/lists of spike times. For example, `[[10, 20]*ms, [15]*ms]` if you have two inputs and the neuron should spike at 10ms and 20ms for the first input, and only once at 15ms for the second input.  
Best,  
Marcel