Main controls to work with graphs are placed above list of graphs:

This panel allows:

Downsampling is designed to smooth the displayed graphs. The smaller the downsampling value, the more detailed the graph will be based on more points. It is worth considering that when selecting a grouping in one minute and plotting, for example, over the past year, the plotting speed is reduced. 

In the upper right corner of chart headings there are individual manage elements:


change scalling values

export of data on which the graph is plotted, in CSV format

change of graphs type: linear, histogram

display values in table under graphs

change charts color

hide/show grahs

delete graphs

Square colored marker allows to change graph color.

Buttons with '+' and '-' signs expand and collapse section, as well as a click on the section header.

Button with 'x' sign deletes the graph from the list.

There is also "Scale values" slider for multigraphs, that makes it possible to compare data with different dimensionality. E.g. you check CPU load and get  metric with 0-4 range and  metric with 0-100 range. In this case  graph will look like straight line because of its tiny range comparing to  one. So "Scale values" feature allows to normalize values of such metrics from different objects for their better visualisation and understanding.