# Data Analysis **URL:** https://ask.igwn.org/c/data-analysis/6.md?page=1 [Latest](https://ask.igwn.org/latest.md) · [Categories](https://ask.igwn.org/categories.md) · [Tags](https://ask.igwn.org/tags.md) **Page:** 2 --- ## [Aux channel list on O4a not updated](https://ask.igwn.org/t/aux-channel-list-on-o4a-not-updated/1386)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 5\ **Last updated:** [September 2, 2025, 2:03am UTC](https://ask.igwn.org/t/aux-channel-list-on-o4a-not-updated/1386 "2025-09-02T02:03:53Z")
Is anyone working on the auxiliary channel uploads on GWOSC for O4a? The channel list does not seem to be complete list the O3. Sampling rates are missing and too few channels. Also, somehow this list was on there since … --- ## [Reality-check: can anyone reproduce (or refute) my “echo” candidates with a \*standard\* PyCBC / GWOSC workflow?](https://ask.igwn.org/t/reality-check-can-anyone-reproduce-or-refute-my-echo-candidates-with-a-standard-pycbc-gwosc-workflow/1332)
**Author:** [@stefan](https://ask.igwn.org/u/stefan)\ **Replies:** 1\ **Last updated:** [July 5, 2025, 6:30pm UTC](https://ask.igwn.org/t/reality-check-can-anyone-reproduce-or-refute-my-echo-candidates-with-a-standard-pycbc-gwosc-workflow/1332 "2025-07-05T18:30:00Z")
Hi everyone, I’ve written my own standalone Python script (not a PyCBC workflow) that scans a small set of O2/O3 GWOSC HDF5 frames for post-merger “quantum-foam echo” signals. The script is attached below as analyse2\_pn… --- ## [Old versions of packages](https://ask.igwn.org/t/old-versions-of-packages/1312)
**Author:** [@Lydia](https://ask.igwn.org/u/Lydia)\ **Replies:** 0\ **Last updated:** [May 22, 2025, 12:03pm UTC](https://ask.igwn.org/t/old-versions-of-packages/1312 "2025-05-22T12:03:25Z")
We’re working on a project that involves using older versions of lalsuite, gwpy, gwosc, and bilby. Specifically we want to use the versions in use during O1 (‘lalsuite==6.82’ ‘bilby==1.1.5’ ‘gwpy==2.0.2’ ‘gwosc==0.5.4’). … --- ## [Calculating SNR from GWTC reported values and PSD](https://ask.igwn.org/t/calculating-snr-from-gwtc-reported-values-and-psd/1265)
**Author:** [@melbouhaddouti](https://ask.igwn.org/u/melbouhaddouti)\ **Replies:** 2\ **Last updated:** [May 8, 2025, 8:59pm UTC](https://ask.igwn.org/t/calculating-snr-from-gwtc-reported-values-and-psd/1265 "2025-05-08T20:59:41Z")
Dear colleague, I attempted to calculate SNRs using the reported values in GWTC for primary masses, secondary masses, redshifts and using PSDs obtained from GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo… --- ## [Review and sample for OSDF based data fetch](https://ask.igwn.org/t/review-and-sample-for-osdf-based-data-fetch/1255)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 0\ **Last updated:** [May 4, 2025, 3:30pm UTC](https://ask.igwn.org/t/review-and-sample-for-osdf-based-data-fetch/1255 "2025-05-04T15:30:08Z")
Wanted to share a review on the new large documents fetching system that GWOSC has implemented to replace the CERN VMFS with OSDF. I used Pelican based script to fetch the entire length of O3a run’s strain data and in c… --- ## [Has anyone used Pyinstaller to pack Framel into exe and it worked?](https://ask.igwn.org/t/has-anyone-used-pyinstaller-to-pack-framel-into-exe-and-it-worked/1236)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 0\ **Last updated:** [April 21, 2025, 6:48pm UTC](https://ask.igwn.org/t/has-anyone-used-pyinstaller-to-pack-framel-into-exe-and-it-worked/1236 "2025-04-21T18:48:39Z")
I am trying to pack a GUI based interface that fetches gwf files from nds servers and as I’m running it on windows, framel is only option out of all GWF APIs. Problem is when I packaged the software into an exe file, eve… --- ## [How to crop the spectogram](https://ask.igwn.org/t/how-to-crop-the-spectogram/1210)
**Author:** [@Jorianta](https://ask.igwn.org/u/Jorianta)\ **Replies:** 2\ **Last updated:** [April 13, 2025, 2:57pm UTC](https://ask.igwn.org/t/how-to-crop-the-spectogram/1210 "2025-04-13T14:57:22Z")
Hello, I am wondering how the time and frequency bounds for the spectograms on the website are determined. I am attempting to programmatically center on the event and determine frequency and time bounds to show the just … --- ## [Is there a way to fetch Main strain channel data without noise or events?](https://ask.igwn.org/t/is-there-a-way-to-fetch-main-strain-channel-data-without-noise-or-events/1197)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 5\ **Last updated:** [March 20, 2025, 5:51pm UTC](https://ask.igwn.org/t/is-there-a-way-to-fetch-main-strain-channel-data-without-noise-or-events/1197 "2025-03-20T17:51:23Z")
I want to fetch O3a run’s strain data that when the detector is in idle state as in when no astrophysical events and no noise from aux channels are detected. Is there any function within gwpy to fetch this or would I hav… --- ## [Tweaking Bilby to ensure convergence of the sampler](https://ask.igwn.org/t/tweaking-bilby-to-ensure-convergence-of-the-sampler/1200)
**Author:** [@Wout](https://ask.igwn.org/u/Wout)\ **Replies:** 0\ **Last updated:** [March 11, 2025, 4:01pm UTC](https://ask.igwn.org/t/tweaking-bilby-to-ensure-convergence-of-the-sampler/1200 "2025-03-11T16:01:41Z")
Dear all, I am working on creating some code that performs a parameter fit for a binary black hole merger (GW150914). I am using Bilby for this; specifically, I am using the Dynesty sampler. However, I am having issues … --- ## [Is there a paper listing the causes of all O3a run's aux channels noise sources?](https://ask.igwn.org/t/is-there-a-paper-listing-the-causes-of-all-o3a-runs-aux-channels-noise-sources/1198)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 3\ **Last updated:** [March 11, 2025, 12:50pm UTC](https://ask.igwn.org/t/is-there-a-paper-listing-the-causes-of-all-o3a-runs-aux-channels-noise-sources/1198 "2025-03-11T12:50:37Z")
I think I had seen a paper listing a sources (of non astrophysical origin) of noise for O3a run’s auxiliary channels but cannot seem to find it. To be specific, there was a mention of one of the air compressors I think … --- ## [Access of O3 Alternate Calibration Release via GWpy](https://ask.igwn.org/t/access-of-o3-alternate-calibration-release-via-gwpy/1116)
**Author:** [@tomkimpson](https://ask.igwn.org/u/tomkimpson)\ **Replies:** 6\ **Last updated:** [February 28, 2025, 11:04pm UTC](https://ask.igwn.org/t/access-of-o3-alternate-calibration-release-via-gwpy/1116 "2025-02-28T23:04:57Z")
Hi all, The example Python/GWPy command for accessing O3 alternate calibration data on the GWOSC webpage does not seem to work for me. from gwpy.timeseries import TimeSeries data = TimeSeries.fetch('H1:DCS-CALIB\_STRAIN… --- ## [Q-transform projections do not show chirp signature](https://ask.igwn.org/t/q-transform-projections-do-not-show-chirp-signature/1166)
**Author:** [@dhegde](https://ask.igwn.org/u/dhegde)\ **Replies:** 4\ **Last updated:** [February 12, 2025, 7:00pm UTC](https://ask.igwn.org/t/q-transform-projections-do-not-show-chirp-signature/1166 "2025-02-12T19:00:37Z")
I am simulating a few microlensed GW signals and trying to get their QTs using gwpy, but many signals do not show the “chirp” signature even after changing various settings of the q\_transform function. For example, I ha… --- ## [Problem to wave using the high-order waveform approximant](https://ask.igwn.org/t/problem-to-wave-using-the-high-order-waveform-approximant/1162)
**Author:** [@lupinlin](https://ask.igwn.org/u/lupinlin)\ **Replies:** 1\ **Last updated:** [January 31, 2025, 5:51am UTC](https://ask.igwn.org/t/problem-to-wave-using-the-high-order-waveform-approximant/1162 "2025-01-31T05:51:07Z")
To simply check the frequency evolution of the high-order time-domain (TD) waveform (i.e., SEOBNRv4HM\_ROM), I performed the following code by the google colab: import matplotlib.pyplot as pp from pycbc import waveform … --- ## [Overplot the Numerical Relativity simulation waveform and the real extracted GW data](https://ask.igwn.org/t/overplot-the-numerical-relativity-simulation-waveform-and-the-real-extracted-gw-data/1111)
**Author:** [@darsh](https://ask.igwn.org/u/darsh)\ **Replies:** 4\ **Last updated:** [January 25, 2025, 11:29pm UTC](https://ask.igwn.org/t/overplot-the-numerical-relativity-simulation-waveform-and-the-real-extracted-gw-data/1111 "2025-01-25T23:29:25Z")
Hi!!..I am facing issues in plotting the real extracted GW signal and the NR signal from the SXS catalog together. I have seen that plot in most of the papers but I am facing issues in plotting it. Can anyone suggest an … --- ## [Finding Strain h and Merger Time](https://ask.igwn.org/t/finding-strain-h-and-merger-time/1121)
**Author:** [@Noor](https://ask.igwn.org/u/Noor)\ **Replies:** 3\ **Last updated:** [January 25, 2025, 8:46pm UTC](https://ask.igwn.org/t/finding-strain-h-and-merger-time/1121 "2025-01-25T20:46:49Z")
How can I find the strain h or the maximum strain h\_max for each event? I need to find them to use them for GWs luminosity calculations. Another question is how to find the merger time? If I understood correctly, merger… --- ## [Helixing results](https://ask.igwn.org/t/helixing-results/1164)
**Author:** [@Julian](https://ask.igwn.org/u/Julian)\ **Replies:** 0\ **Last updated:** [January 21, 2025, 2:10am UTC](https://ask.igwn.org/t/helixing-results/1164 "2025-01-21T02:10:46Z")
At its core, recursive dynamics refers to iterative processes where energy or information is transferred across different dimensions, whether spatial or temporal. Each interaction influences the subsequent iterations, cr… --- ## [Definition of "end time of merger time" in GWOSC event list](https://ask.igwn.org/t/definition-of-end-time-of-merger-time-in-gwosc-event-list/1056)
**Author:** [@yidelee](https://ask.igwn.org/u/yidelee)\ **Replies:** 6\ **Last updated:** [January 17, 2025, 2:27pm UTC](https://ask.igwn.org/t/definition-of-end-time-of-merger-time-in-gwosc-event-list/1056 "2025-01-17T14:27:32Z")
Dear colleagues, The Event List from GWOSC records the GPS time of each event, where GPS time is said to be " End time or merger time of the event in GPS seconds" in Event Portal Usage Notes. I wonder what is the defini… --- ## [How to select the psd-model when PEing GW150915 real data with PyCBC pycbc\_inference executables?](https://ask.igwn.org/t/how-to-select-the-psd-model-when-peing-gw150915-real-data-with-pycbc-pycbc-inference-executables/1156)
**Author:** [@chendawww](https://ask.igwn.org/u/chendawww)\ **Replies:** 2\ **Last updated:** [December 18, 2024, 4:23pm UTC](https://ask.igwn.org/t/how-to-select-the-psd-model-when-peing-gw150915-real-data-with-pycbc-pycbc-inference-executables/1156 "2024-12-18T16:23:52Z")
There’re many optionable psd models for injecting a noise psd morphology in the PyCBC modules that is mainly produced from LALSimulation. (like psd-model=aLGOxxxxxx as a parameter setting inside \[data\] section of ini. … --- ## [Omicron unable to accept time series file](https://ask.igwn.org/t/omicron-unable-to-accept-time-series-file/1158)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 2\ **Last updated:** [December 17, 2024, 7:35pm UTC](https://ask.igwn.org/t/omicron-unable-to-accept-time-series-file/1158 "2024-12-17T19:35:05Z")
I have been able to initiate Omicron after much trial and error, however now I am stuck with an error. Using a list of gps times for H1 for O3a run from https://gwosc.org/O3/auxiliary/, also attached to this email, I ha… --- ## [GWs event parameter estimation posterior](https://ask.igwn.org/t/gws-event-parameter-estimation-posterior/1135)
**Author:** [@Raghad](https://ask.igwn.org/u/Raghad)\ **Replies:** 1\ **Last updated:** [December 17, 2024, 5:16pm UTC](https://ask.igwn.org/t/gws-event-parameter-estimation-posterior/1135 "2024-12-17T17:16:14Z")
Hello. I have some questions about the h5 datasets files that I found in LIGO documentation Regarding the parameter estimation posterior events of the released datasets, what is the essential difference between a Cosmo… --- ## [Redshift, luminosity distance](https://ask.igwn.org/t/redshift-luminosity-distance/1136)
**Author:** [@Raghad](https://ask.igwn.org/u/Raghad)\ **Replies:** 3\ **Last updated:** [November 16, 2024, 5:17pm UTC](https://ask.igwn.org/t/redshift-luminosity-distance/1136 "2024-11-16T17:17:42Z")
Hello everyone. We infer the luminosity distance from the detector data; once we get the luminosity distance, we estimate the redshift. How exactly do we estimate the redshift, and does the analysis differ from what th… --- ## [Spin-aligned waveforms IMRPhenomXHM and SEOBNRv4HM\_ROM unable to recover injected parameters](https://ask.igwn.org/t/spin-aligned-waveforms-imrphenomxhm-and-seobnrv4hm-rom-unable-to-recover-injected-parameters/1139)
**Author:** [@CalTNG](https://ask.igwn.org/u/CalTNG)\ **Replies:** 0\ **Last updated:** [November 11, 2024, 4:06pm UTC](https://ask.igwn.org/t/spin-aligned-waveforms-imrphenomxhm-and-seobnrv4hm-rom-unable-to-recover-injected-parameters/1139 "2024-11-11T16:06:01Z")
Hello, I am studying EOB waveforms SEOBNRv4HM\_ROM, but I’ve found something weird. I injected a GW190521-like signal and used Bilby to perform parameter estimation. I only estimated four parameters: chirp mass, mass rat… --- ## [Choosing the prior](https://ask.igwn.org/t/choosing-the-prior/1123)
**Author:** [@Courtney](https://ask.igwn.org/u/Courtney)\ **Replies:** 3\ **Last updated:** [November 4, 2024, 7:26pm UTC](https://ask.igwn.org/t/choosing-the-prior/1123 "2024-11-04T19:26:28Z")
Hello, I’m following tutorial 3.2 for non-spinning parameter estimation. Using this code, what parameter can we estimate other than the chirp mass? Also, would it apply to signals such as GW230529, where I can choose an… --- ## [Gravitational wave research](https://ask.igwn.org/t/gravitational-wave-research/1092)
**Author:** [@Raghadrashid](https://ask.igwn.org/u/Raghadrashid)\ **Replies:** 4\ **Last updated:** [October 23, 2024, 6:23pm UTC](https://ask.igwn.org/t/gravitational-wave-research/1092 "2024-10-23T18:23:40Z")
I’m doing research on GWs for my senior project. Is two months a reasonable duration for doing that? I have a background in GWs but I will start learning data analysis from scratch. What are the potential of researching … --- ## [Confusing Results when setting different fMin for SEOBNR waveforms](https://ask.igwn.org/t/confusing-results-when-setting-different-fmin-for-seobnr-waveforms/1119)
**Author:** [@CalTNG](https://ask.igwn.org/u/CalTNG)\ **Replies:** 0\ **Last updated:** [October 14, 2024, 3:04pm UTC](https://ask.igwn.org/t/confusing-results-when-setting-different-fmin-for-seobnr-waveforms/1119 "2024-10-14T15:04:36Z")
Hi, while working on some practice tasks using pyCBC, I encountered something unexpected when trying to generate several FD waveforms by converting waveforms originally in TD into FD using to\_frequencies() method. I ge… --- ## [How to use my own waveforms or interferometer in bilby and pbilby?](https://ask.igwn.org/t/how-to-use-my-own-waveforms-or-interferometer-in-bilby-and-pbilby/1114)
**Author:** [@CalTNG](https://ask.igwn.org/u/CalTNG)\ **Replies:** 4\ **Last updated:** [October 8, 2024, 7:04am UTC](https://ask.igwn.org/t/how-to-use-my-own-waveforms-or-interferometer-in-bilby-and-pbilby/1114 "2024-10-08T07:04:29Z")
Hi, I am using some waveforms not included in LALsuite (as well as LALsuite-extra) to analyze several GW events. However, I encountered some troubles when trying to use them in bilby as I am following the example create\_… --- ## [Question about data analysis gravitational wave candidates](https://ask.igwn.org/t/question-about-data-analysis-gravitational-wave-candidates/1109)
**Author:** [@salanl](https://ask.igwn.org/u/salanl)\ **Replies:** 4\ **Last updated:** [October 5, 2024, 4:23pm UTC](https://ask.igwn.org/t/question-about-data-analysis-gravitational-wave-candidates/1109 "2024-10-05T16:23:51Z")
Peace upoan you all. I’m doing a research project, I want to use the skill and follow the same process that I’ve learned in the Gravitational Wave Open Data Workshop 2024. Is it possible to use the candidate events (Not … --- ## [GW events catalog single detector SNR](https://ask.igwn.org/t/gw-events-catalog-single-detector-snr/1103)
**Author:** [@BarryG](https://ask.igwn.org/u/BarryG)\ **Replies:** 2\ **Last updated:** [September 25, 2024, 8:18am UTC](https://ask.igwn.org/t/gw-events-catalog-single-detector-snr/1103 "2024-09-25T08:18:14Z")
Hi everyone: I am working on a project that processes the strain data on detectors. In one of the steps, the SNR of GW events is crucial for me to test my method, but sadly only the information about network SNR is foun… --- ## [Detector Noise For data simulation](https://ask.igwn.org/t/detector-noise-for-data-simulation/1104)
**Author:** [@Rao](https://ask.igwn.org/u/Rao)\ **Replies:** 3\ **Last updated:** [September 24, 2024, 7:27pm UTC](https://ask.igwn.org/t/detector-noise-for-data-simulation/1104 "2024-09-24T19:27:45Z")
How one can download the detector noise (without signals or glitches) from all 3 observations ? --- ## [Questions about Input Domain Error and Usage of Eccentric Waveform Approximants](https://ask.igwn.org/t/questions-about-input-domain-error-and-usage-of-eccentric-waveform-approximants/1095)
**Author:** [@CalTNG](https://ask.igwn.org/u/CalTNG)\ **Replies:** 4\ **Last updated:** [September 24, 2024, 10:08am UTC](https://ask.igwn.org/t/questions-about-input-domain-error-and-usage-of-eccentric-waveform-approximants/1095 "2024-09-24T10:08:25Z")
Hello, I am an undergraduate student working on a project about GW, and I met some problems when I was trying to replicate LIGO’s results for GW190521 with parallel bilby and SEOBNR waveforms. In my analysis, I applied … [Previous page](https://ask.igwn.org/c/data-analysis/6.md) [Next page](https://ask.igwn.org/c/data-analysis/6.md?page=2)