Dear Tim, dear Matt,
Thank you very much for your helpful answers. Sorry that I may not described very clearly before. As Tim mentioned, we used the -metric-extrema to find the maximum point within a certain region (produce "maxima.func.gii" file) and then use the -metric-rois-from-extrema to draw ROIs (produced "ROI.func.gii" file). Then there is a contradictory thing emerged. When we used "wb_command -metric-stats ROI.func.gii -reduce -SUM "to count the ROI vertex number, a few results showed two values, which might indicate two ROIs based on the two maximum points. We checked the maxima.func.gii files, and found there do existed two maximum points in such condition. However, when we looked at the created ROI images on Connectome Workbench, we only saw one target ROI drawn on the brain surface. This confused us a lot. We don't know whether there were one or two ROIs produced. Do you have any suggestions about that? Thanks. Best regards, Xinyang At 2018-08-25 04:16:48, "Timothy Coalson" <[email protected]> wrote: The -metric-extrema command doesn't draw ROIs, it sets single vertices to 1 or -1 based on if they are a local maximum or minimum. By default, if there are two equal values that are closer than the search range, then *neither* of them will be identified as an extrema. If they are further then the search range, then both may be extrema. The -consolidate-mode acts somewhat differently - if two equal values are touching, neither is treated as an initial extrema, but as long as there is at least one vertex separating them, they may both be treated as initial extrema. After the initial extrema are found, all extrema that are close to other extrema are "consolidated" together. The details are somewhat complicated, and it was implemented by request of others, it is not something that we use. Tim On Fri, Aug 24, 2018 at 7:11 AM, Xinyang Liu <[email protected]> wrote: Hi, Matt. Thank you very much for your reply. The extreme point was searched in a certain surface area. Do you mean that even there are two maximum points with the same value, they were controlled in a limited distance and therefore, the final drawn ROI is a combined region of two drawings instead of two separate ones? Because the problem is that, when I count the total vertex number for each created ROI using -metric-stats, a few results showed two values for one ROI. I am wondering why this happen and how to deal with that. Best regards, Xinyang At 2018-08-24 19:14:56, "Glasser, Matthew" <[email protected]> wrote: I believe there is a configurable setting that sets the minimum distance between extrema. It is a local min/max that is found. Matt. From: <[email protected]> on behalf of Xinyang Liu <[email protected]> Date: Friday, August 24, 2018 at 4:21 AM To: HCP 讨论组 <[email protected]> Subject: [HCP-Users] two maximum points using -metric-extrema Dear HCP experts, Hi. When using workbench command "-metric-extrema" to draw ROI around the maximum point of the fMRI surface region, what would happen if there are two maximum points? Will the software keep both of them or only keep one? Thanks a lot. Best regards, Xinyang _______________________________________________ HCP-Users mailing list [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail. _______________________________________________ HCP-Users mailing list [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users _______________________________________________ HCP-Users mailing list [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users
