This code is written in python (3.x) and requires numpy, matplotlib and pandas.

Example call: 
python expense_plotter.py ../expense-reports/ costco hpp bulk \
--names "Costco" "Hyde Park Produce" "Bulk" --budget 900 850 900 \
--output_filetype .png 

where the folder ../expense-reports/ contains:
../expense-reports/bulk_FY16-17.xlsx
../expense-reports/bulk_FY17-18.xlsx
../expense-reports/costco_FY16-17.xlsx
../expense-reports/costco_FY17-18.xlsx
../expense-reports/hpp_FY16-17.xlsx
../expense-reports/hpp_FY17-18.xlsx

which are lists of transactions generated by Quickbooks.

usage: expense_plotter.py [-h] [-o OUTPUT] [-t OUTPUT_FILETYPE]
                          [-y [YEARS [YEARS ...]]] [-n [NAMES [NAMES ...]]]
                          [-e EXTENSION] [-c COLUMN_TITLE] [-b BINSIZE]
                          [-s SMOOTH_WINDOW] [-m MAIN_PLOT]
                          [-p PLOT_SIZE PLOT_SIZE] [-x] [-a]
                          [--budgets [BUDGETS [BUDGETS ...]]]
                          folder [to_plot [to_plot ...]]

script for plotting expense reports from Quickbooks

positional arguments:
  folder                folder containing expense reports generated by
                        Quickbooks
  to_plot

optional arguments:
  -h, --help            show this help message and exit
  -o OUTPUT, --output OUTPUT
                        filename to save output plot in
  -t OUTPUT_FILETYPE, --output_filetype OUTPUT_FILETYPE
                        filetype to save output as
  -y [YEARS [YEARS ...]], --years [YEARS [YEARS ...]]
                        years to plot
  -n [NAMES [NAMES ...]], --names [NAMES [NAMES ...]]
                        long names of everything to plot, given in the same
                        order
  -e EXTENSION, --extension EXTENSION
                        data filetype extension
  -c COLUMN_TITLE, --column_title COLUMN_TITLE
                        the title of the column containing spending amounts
  -b BINSIZE, --binsize BINSIZE
                        the size of the bins (in days) to use when plotting
                        (default 30)
  -s SMOOTH_WINDOW, --smooth_window SMOOTH_WINDOW
                        the width of the smoothing window to use, if smoothing
                        is set to true (default 60)
  -m MAIN_PLOT, --main_plot MAIN_PLOT
                        the string corresponding to the file names that will
                        be plotted in a bigger plot in a top row
  -p PLOT_SIZE PLOT_SIZE, --plot_size PLOT_SIZE PLOT_SIZE
                        the size (in inches, width height) of the plot to
                        generate
  -x, --smooth          whether to apply smoothing (default True)
  -a, --average         whether to plot average amounts on the righthand side
                        of the plot
  --budgets [BUDGETS [BUDGETS ...]]
                        the amounts budgeted for each category, listed in the
                        same order as the categories -- or only one value if
                        the budgets were all the same