DoHeatmap: Gene expression heatmap
In mayer-lab/SeuratForMayer2018: Seurat : R Toolkit for Single Cell Genomics

Draws a heatmap of single cell gene expression using ggplot2.

DoHeatmap(object, data.use = NULL, use.scaled = TRUE, cells.use = NULL,
  genes.use = NULL, disp.min = -2.5, disp.max = 2.5, group.by = "ident",
  draw.line = TRUE, col.low = "#FF00FF", col.mid = "#000000",
  col.high = "#FFFF00", slim.col.label = FALSE, remove.key = FALSE,
  rotate.key = FALSE, title = NULL, cex.col = 10, cex.row = 10,
  group.label.loc = "bottom", group.label.rot = FALSE, group.cex = 15,
  group.spacing = 0.15, do.plot = TRUE)

`object`	Seurat object
`data.use`	Option to pass in data to use in the heatmap. Default will pick from either object@data or object@scale.data depending on use.scaled parameter. Should have cells as columns and genes as rows.
`use.scaled`	Whether to use the data or scaled data if data.use is NULL
`cells.use`	Cells to include in the heatmap (default is all cells)
`genes.use`	Genes to include in the heatmap (ordered)
`disp.min`	Minimum display value (all values below are clipped)
`disp.max`	Maximum display value (all values above are clipped)
`group.by`	Groups cells by this variable. Default is object@ident
`draw.line`	Draw vertical lines delineating different groups
`col.low`	Color for lowest expression value
`col.mid`	Color for mid expression value
`col.high`	Color for highest expression value
`slim.col.label`	display only the identity class name once for each group
`remove.key`	Removes the color key from the plot.
`rotate.key`	Rotate color scale horizantally
`title`	Title for plot
`cex.col`	Controls size of column labels (cells)
`cex.row`	Controls size of row labels (genes)
`group.label.loc`	Place group labels on bottom or top of plot.
`group.label.rot`	Whether to rotate the group label.
`group.cex`	Size of group label text
`group.spacing`	Controls amount of space between columns.
`do.plot`	Whether to display the plot.