Dear Tim, dear Glasser,
Thank you very much for your answers. That's very clear to me now. :) By the way, I also have a question when counting the vertex number of surface ROIs (.func.gii) using the wb_command -metric-stats -reduce SUM. Among around 200 subjects, there are two subjects whose vertex number outcomes are two sum values (e.g. 63 97 in a column), which is strange. Do you know the possible reason for that? Thanks. Best regards, Xinyang At 2018-06-08 05:15:36, "Timothy Coalson" <tsc...@mst.edu> wrote: A picture is worth a thousand words, so here is a single subject 32k fs_LR surface, rendered to show edges between vertices, showing the variable spacing (you can check this on other surfaces by loading them in wb_view, and going to the Surface menu, clicking Properties, and setting "Drawin Type" to "Links (Edges)". In short, you shouldn't think of vertices like you do voxels, they don't use a fully regular grid. This is why wb_command spatial operations take nearly all distances in mm, not in neighbors. Tim On Thu, Jun 7, 2018 at 10:48 AM, Glasser, Matthew <glass...@wustl.edu> wrote: On a standard mesh anatomical surface the vertex spacing is non-uniform across the surface. If you used the spheres you could get a uniform number of vertices (though now the patches would cover different total areas). Probably the uniform in mm approach (on the midthickness with appropriate correction for shrinkage by vertex areas) is what you want. Peace, Matt. From: <hcp-users-boun...@humanconnectome.org> on behalf of Xinyang Liu <xinyang_ie...@163.com> Date: Thursday, June 7, 2018 at 8:33 AM To: HCP 讨论组 <hcp-users@humanconnectome.org> Subject: [HCP-Users] wb_command -metric-rois-from-extrema Dear HCP experts, Hi. I have some confusions when using the workbench command -metric-rois-from-extrema. When using it to draw ROIs on the fMRI surface, I found that with the same radium, the number of vertices inside the ROI can be different in different locations. For example, when r=5mm, the vertex number can range from around 30 to around 80. Maybe I do not understand very well about the parameter <limit> - geodesic distance limit from vertex, in mm. My understanding is that the distance is the radium around the extrema on the stretched surface, and the vertex numbers should be the same after the radium is set. Where do I misunderstand? Look forward to any kind guidance. Thanks a lot. Best regards, Xinyang _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users
