Dear FS team, I processed two set of MRI data for a single patient,Thats BL scan and TP1.I ran both scans on a Mcbook Pro and a PC with Virtual machine installed. Though I was expecting the same segstats,the results vary from Macpro to VM.For eg , for BL in Mac SubCortGrayVol is 178038 but for the same images in VM the results are 177432.Does it happened to any one before....Whats the reson its happening and how can I remedy,validate the results. Much appreciate your advice,... In Thanks Chikku.
Hi Chikku, while we try to resolve these differences, you are not guaranteed to get identical results when you use different platforms. This is an issue with using different computes and applies to all software, not just FS.It is caused by the use of different math libraries and different binary operations. The difference you show is only 0.3% which should not be enough to cause false results. doug
On 01/22/2013 08:13 AM, Varghese Chikku wrote:
Dear FS team, I processed two set of MRI data for a single patient,Thats BL scan and TP1.I ran both scans on a Mcbook Pro and a PC with Virtual machine installed. Though I was expecting the same segstats,the results vary from Macpro to VM.For eg , for BL in Mac SubCortGrayVol is 178038 but for the same images in VM the results are 177432.Does it happened to any one before....Whats the reson its happening and how can I remedy,validate the results. Much appreciate your advice,... In Thanks Chikku.
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
also there is an issue in v5.1 where the second run of recon-all on a given platform will produce different results from the first (but subsequent runs should produce identical results). this issue has been fixed in the upcoming v5.2 release.
nick
On Tue, 2013-01-22 at 10:18 -0500, Douglas N Greve wrote:
Hi Chikku, while we try to resolve these differences, you are not guaranteed to get identical results when you use different platforms. This is an issue with using different computes and applies to all software, not just FS.It is caused by the use of different math libraries and different binary operations. The difference you show is only 0.3% which should not be enough to cause false results. doug
On 01/22/2013 08:13 AM, Varghese Chikku wrote:
Dear FS team, I processed two set of MRI data for a single patient,Thats BL scan and TP1.I ran both scans on a Mcbook Pro and a PC with Virtual machine installed. Though I was expecting the same segstats,the results vary from Macpro to VM.For eg , for BL in Mac SubCortGrayVol is 178038 but for the same images in VM the results are 177432.Does it happened to any one before....Whats the reson its happening and how can I remedy,validate the results. Much appreciate your advice,... In Thanks Chikku.
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Hi Nick,
Could you clarify this? So if we re-run a subject in 5.1 (say after doing some edits), we would then need to run it again a third time in order to maintain consistency? Thanks.
-Derin
On Jan 22, 2013, at 2:17 PM, Nick Schmansky nicks@nmr.mgh.harvard.edu wrote:
also there is an issue in v5.1 where the second run of recon-all on a given platform will produce different results from the first (but subsequent runs should produce identical results). this issue has been fixed in the upcoming v5.2 release.
nick
On Tue, 2013-01-22 at 10:18 -0500, Douglas N Greve wrote:
Hi Chikku, while we try to resolve these differences, you are not guaranteed to get identical results when you use different platforms. This is an issue with using different computes and applies to all software, not just FS.It is caused by the use of different math libraries and different binary operations. The difference you show is only 0.3% which should not be enough to cause false results. doug
On 01/22/2013 08:13 AM, Varghese Chikku wrote:
Dear FS team, I processed two set of MRI data for a single patient,Thats BL scan and TP1.I ran both scans on a Mcbook Pro and a PC with Virtual machine installed. Though I was expecting the same segstats,the results vary from Macpro to VM.For eg , for BL in Mac SubCortGrayVol is 178038 but for the same images in VM the results are 177432.Does it happened to any one before....Whats the reson its happening and how can I remedy,validate the results. Much appreciate your advice,... In Thanks Chikku.
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
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Derin J Cobia -
Douglas N Greve -
Nick Schmansky -
Varghese Chikku