diff options
| author | Aaron LI <aly@aaronly.me> | 2019-01-28 16:51:03 +0800 |
|---|---|---|
| committer | Aaron LI <aly@aaronly.me> | 2019-01-28 16:51:03 +0800 |
| commit | fd0f784f5c9951543d06c5be8c6508fbfe0924e2 (patch) | |
| tree | a1ca1307a340aa0dff78d8395d06d5daa4cf877a /fg21sim/utils | |
| parent | 8c96ca33ca76d6b593da74817a4b68c52da7b80f (diff) | |
| download | fg21sim-fd0f784f5c9951543d06c5be8c6508fbfe0924e2.tar.bz2 | |
utils/analyze: Add logfit()
This function helps fit the index of a scaling relation.
Diffstat (limited to 'fg21sim/utils')
| -rw-r--r-- | fg21sim/utils/analyze.py | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/fg21sim/utils/analyze.py b/fg21sim/utils/analyze.py index ad9f1b4..f33f65c 100644 --- a/fg21sim/utils/analyze.py +++ b/fg21sim/utils/analyze.py @@ -1,5 +1,5 @@ -# Copyright (c) 2017 Weitian LI <weitian@aaronly.me> -# MIT license +# Copyright (c) 2017,2019 Weitian LI <wt@liwt.net> +# MIT License """ Utilities to help analyze the simulation results. @@ -77,3 +77,28 @@ def countdist_integrated(x, nbin, log=True, xmin=None, xmax=None): binedges = np.exp(binedges) return (counts, bins, binedges) + + +def logfit(x, y): + """ + Fit the data points with: y = a * x^b + + Parameters + ---------- + x, y : list[float] + The data points. + + Returns + ------- + coef : (a, b) + The fitted coefficients. + fp : function + The function with fitted coefficients to calculate the fitted + values: fp(x). + """ + logx = np.log(x) + logy = np.log(y) + fit = np.polyfit(logx, logy, deg=1) + coef = (np.exp(fit[1]), fit[0]) + fp = lambda x: np.exp(np.polyval(fit, np.log(x))) + return coef, fp |