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Srivastava Lab

Runs FindNeighbors on the embedded Seurat object and returns the updated MatisseObject. Typically called after RunPCA.MatisseObject and before FindClusters.MatisseObject.

Usage

# S3 method for class 'MatisseObject'
FindNeighbors(
  object,
  reduction = "pca",
  dims = 1:10,
  assay = NULL,
  features = NULL,
  k.param = 20,
  return.neighbor = FALSE,
  compute.SNN = !return.neighbor,
  prune.SNN = 1/15,
  nn.method = "annoy",
  n.trees = 50,
  annoy.metric = "euclidean",
  nn.eps = 0,
  verbose = TRUE,
  do.plot = FALSE,
  graph.name = NULL,
  l2.norm = FALSE,
  cache.index = FALSE,
  ...
)

Arguments

object

A MatisseObject.

reduction

Reduction to use as input for building the (S)NN

dims

Dimensions of reduction to use as input

assay

Assay to use in construction of (S)NN; used only when dims is NULL

features

Features to use as input for building the (S)NN; used only when dims is NULL

k.param

Defines k for the k-nearest neighbor algorithm

return.neighbor

Return result as Neighbor object. Not used with distance matrix input.

compute.SNN

also compute the shared nearest neighbor graph

prune.SNN

Sets the cutoff for acceptable Jaccard index when computing the neighborhood overlap for the SNN construction. Any edges with values less than or equal to this will be set to 0 and removed from the SNN graph. Essentially sets the stringency of pruning (0 — no pruning, 1 — prune everything).

nn.method

Method for nearest neighbor finding. Options include: rann, annoy

n.trees

More trees gives higher precision when using annoy approximate nearest neighbor search

annoy.metric

Distance metric for annoy. Options include: euclidean, cosine, manhattan, and hamming

nn.eps

Error bound when performing nearest neighbor search using RANN; default of 0.0 implies exact nearest neighbor search

verbose

Whether or not to print output to the console

do.plot

Plot SNN graph on tSNE coordinates

graph.name

Optional naming parameter for stored (S)NN graph (or Neighbor object, if return.neighbor = TRUE). Default is assay.name_(s)nn. To store both the neighbor graph and the shared nearest neighbor (SNN) graph, you must supply a vector containing two names to the graph.name parameter. The first element in the vector will be used to store the nearest neighbor (NN) graph, and the second element used to store the SNN graph. If only one name is supplied, only the NN graph is stored.

l2.norm

Take L2Norm of the data

cache.index

Include cached index in returned Neighbor object (only relevant if return.neighbor = TRUE)

...

Additional arguments forwarded to FindNeighbors (e.g. dims, reduction).

Value

The updated MatisseObject with neighbour graph stored inside the embedded Seurat object.