# How to compute $\Delta f/ f$ in computational neuroscience? [closed]

I want to compute $\Delta f/f$ (as explained in this link, reference 1), but I am not able to do integration as I have distinct values and no function to generate the continuous time based values.

I have a $1\times N$ time series data where $N$ is the total number of neuron response for one neuron, one for each millisecond. How do I calculate $\Delta f/f$ for this single neuron? If I do $(f_{i+1} - f_{i})/f_{i}$, it gives me very small values.

## References

1. Jia, Hongbo, et al. "In vivo two-photon imaging of sensory-evoked dendritic calcium signals in cortical neurons." Nature protocols 6.1 (2011): 28-35. doi:10.1038/nprot.2010.169
• Welcome to SciComp.SE. Your question, as it is right now, is not clear, and it is difficult that somebody is willing to read the reference and come back to explain it to you. Why do you need to compute $\Delta f/f$? What does this provide to you? – nicoguaro Nov 4 '16 at 19:31
• This is a valid question, but probably not easy to answer since you don't seem to understand most of what the link is telling you. I recommend you talk to a signal processing expert. – Memming Nov 6 '16 at 11:37
• Δf/f is a standard measure of neuronal responses in neuroscience for pretty much all fluorescence imaging experiments. It is pretty simple you just get the mean fluorescence at baseline (call it Fo). Then for each image during the experiment get the fluorescence Ft and deltaF/F is a function of t and is (Ft-Fo)/Fo. This is usually done either per pixel or in an ROI. – neuronet Apr 13 at 20:34
• For instance see this paper: ncbi.nlm.nih.gov/pubmed/22753596 – neuronet Apr 13 at 20:44