dfvue 0.993

General layout

On opening, dfvue presents currently only one panel for producing scatter/line plots. This is the look in macOS light mode (higher resolution images can be found in the documentation):

The pane is organised in this fashion: the plotting canvas, the Matplotlib navigation toolbar and the pane, where one can choose the plotting variables and plotting options. You can open another, identical window for the same csv file with the button “New Window” on the top right. You can then also read in a new csv file in one of the windows with the button “Open File”.

Reading a csv file

The “Read csv file” window opens when a csv file is given.

The csv file can be given on the command line:

dfvue csv_file.csv

from within Python:

from dfvue import dfvue
dfvue('csv_file.csv')

or being selected from the “Choose csv file” selector that opens when hitting the button “Open File”.

The “Read csv file” window reads the first 40 rows of the csv file with pandas’ read_csv method using the options given in the pane. It shows the resulting pandas.DataFrame in tabulated format. Changing focus from one option entry to another, for example by hitting the <tab> key, re-reads the first 40 rows of the csv file with pandas.read_csv using the selected options in the form. Hitting <enter> or <return> within the window reads the entire csv file using the selected options and returns to the plotting panels. This is the same than pressing the “Read csv” button in the lower right corner.

The options in the form are pandas’ read_csv default options except for parse_date, which is set to True instead of False here. Hover over the entry boxes to see explanations of the options in the tooltip.

If the csv file includes a Date/Time column, it is best to set this column as the index of the pandas.DataFrame by using index_col. Correct datetime is indicated if the index has the data type datetime64[ns] in the plot panels. This is then correctly interpreted by the underlying Matplotlib when plotting, zooming, or panning the axes. dfvue sets the index if index_col is used but also provides the original column.

missing_value is not an option of pandas’ read_csv. It is here for convenience and any number entered in missing_value will be added to pandas na_values.

Scatter/Line panel

Here is the Scatter/Line panel in macOS dark mode, describing all buttons, sliders, entry boxes, spinboxes, and menus:

The default plot is a line plot with solid lines (line style ‘ls’ is ‘-‘). One can set line style ‘ls’ to None and set a marker symbol, e.g. ‘o’ for circles, to get a scatter plot. A large variety of line styles, marker symbols and color notations are supported.