Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-10-01 Thread Shannon Kogachi
Hi Martin, I am a little confused about these mapped files in the base directories you are referring to. How would I check them? -Shannon K. On Fri, Sep 28, 2012 at 4:08 PM, Martin Reuter wrote: > I see, > Usually people look at thickness maps and volume on an ROI basis. Volume > on the surface

Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-09-28 Thread Martin Reuter
I see, Usually people look at thickness maps and volume on an ROI basis. Volume on the surface I think is simply area times thickness. Not sure how meaningful that is as area of a vertex depends on the triangle mesh. Anyway, you look at smoothed maps on fsaverage. The average volume for each ve

Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-09-28 Thread Shannon Kogachi
Hi Martin, I am running FS version 5.1. This is the command line I ran: long_mris_slopes --qdec ./qdec/long.qdec.table.dat --meas volume --hemi lh --do-avg --do-rate --do-pc1 --do-spc --do-stack --do-label --time years --qcache fsaverage These are the outputs I get, which are located in the sub

Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-09-28 Thread Martin Reuter
Hi Shannon, that cannot be. It either indicates a serious bug (which we have not yet encountered in our data) or a problem with your processing. Can you send me: - the version you use - the command line you run - the output you get Also long_mris_slopes is designed for analyzing surface maps (an

Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-09-27 Thread Shannon Kogachi
Hi Martin, Each subject has 3-6 timepoints. They are all about one year apart. Here's an example of the discrepancy: one subject with 5 timepoints had volumes that ranged from 2.2-2.4. However, from the long_mris_slopes command, the temporal average volume was calculated to be 1.67. Thanks for yo

Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-09-27 Thread Martin Reuter
Hi Shannon, long_mris_slopes works for surface maps (both thickness and volume should work). In both cases it should compute the temporal average. I have another scripts that works for stats files (long_stats_slopes) in the same way. How many time points do you have, how far apart (equally spac

Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-09-26 Thread Shannon Kogachi
Hi Martin, When I used the long_mris_slopes command for the thickness, the average thickness calculated in FreeSurfer was pretty similar to averaging the values in FreeSurfer. Does this command only work thickness measures and not for volume or area? Thanks! -Shannon On Wed, Sep 26, 2012 at 2

Re: [Freesurfer] long_mris_slopes command: temporal average calculation

2012-09-26 Thread Martin Reuter
Hi Shannon You probably mean average thickness. My scripts compute the temporal average from the linear fit (at mid time), which can be differed from simply averaging values. Best Martin Shannon Kogachi wrote: >Hi, >I had a question about how the temporal average is calculated for >subjects >w