[ https://issues.apache.org/jira/browse/SYSTEMML-1736?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Mike Dusenberry reassigned SYSTEMML-1736: ----------------------------------------- Assignee: Mike Dusenberry (was: Fei Hu) > Add new 2D top_k utility function > --------------------------------- > > Key: SYSTEMML-1736 > URL: https://issues.apache.org/jira/browse/SYSTEMML-1736 > Project: SystemML > Issue Type: Sub-task > Reporter: Mike Dusenberry > Assignee: Mike Dusenberry > > We should add a new {{top_k2d}} utility function (in {{nn/util.dml}}) that > accepts a matrix {{X}} and return matrices {{values}} and {{indices}} with > the top {{k}} values (i.e. probabilities) and associated indices (i.e. > classes) along a certain dimension. This will be modeled after the > [{{top_k}} function in TensorFlow | > https://www.tensorflow.org/api_docs/python/tf/nn/top_k]. For the 2D case, > {{top_k}} will operate on the channels dimension. A typical use case here is > that in which {{X}} is the output of a {{softmax2d}} layer (so each channel > contains a set of normalized class probabilities), and {{values}} and > {{indices}} will contain the top {{k}} probabilities and indices along the > channel axis. This scenario would be common in an image segmentation > problem, in which every pixel of the output image will have a set of class > probabilities along the channel axis. > Having these {{top-k}} functions will allow us to extract either predict a > single class for each item, or the top {{k}} classes, and therefore may be > more useful that a {{predict_class}} function. > Although we will use {{values}} and {{indices}} as the names of the returned > matrices within the functions, in practice, one is likely to name the results > {{probs}} and {{classes}} in the calling environment. -- This message was sent by Atlassian JIRA (v6.4.14#64029)