If you set `maxTooms=0`, please note that IGV and many other tools WILL NOT WORK as they assume that at least one zoom level will be present. You are advised to use the default unless you do not expect the bigWig files to be used by other packages.
## Adding entries to a bigWig file
Assuming you've opened a file for writing and added a header, you can then add entries. Note that the entries **must** be added in order, as bigWig files always contain ordered intervals. There are three formats that bigWig files can use internally to store entries. The most commonly observed format is identical to a [bedGraph](https://genome.ucsc.edu/goldenpath/help/bedgraph.html) file: