I have one monthly data series in one spreadsheet and one quarterly in a different spreadsheet. What is the "smartest" way to plot them together in one graph (in Excel)? Its quite a lot of data, so I would like to avoid fiddling with it manually.
EDIT: The data is laid out in the following way:
Monthly:
2011-12-01 1246.91
2011-11-01 1251
2011-10-03 1131.21
2011-09-01 1219.12
2011-08-01 1292.59
2011-07-01 1320.64
2011-06-01 1345.2
Quarterly:
1947q1 237.2
1947q2 240.4
1947q3 244.5
1947q4 254.3
1948q1 260.3
1948q2 267.3
1948q3 273.8
1948q4 275.1
We can assume that 1947q1 is the same day as the corresponding monthly data for January.
Best Answer
I assume the time span of the quarterly data corresponds to that of the monthly data. I extended the monthly data to include an entire year, and made up corresponding quarterly data, and plotted each separately:
I like bars for the quarterly data, because I can make them wide enough to span the three months of monthly data for each quarter.
To make the chart, start by selecting the monthly data and inserting a line chart. Excel automatically sorts the dates, so they are plotted increasing from left to right (Chart 1 below).
Select and copy the quarterly data, select the chart, and use Home tab > Paste dropdown > Paste Special to add the data as a new series, series in columns, series names in first row, categories in first column. The new series isn't visible (yet).
Select the new series (you can't see it, but if you select the visible series and click the up arrow key, you'll select it), and format it to assign it to the secondary axis. You still can't see it, but Excel has added a secondary vertical axis (Chart 2).
Use the "+" skittle floating beside the chart (Excel 2013+) or the ribbon buttons to add the secondary horizontal axis (Chart 3). Now we're getting somewhere.
This axis isn't automatically sorted, since Excel doesn't recognize 2011Q4 as a date. So format the secondary horizontal axis: check Categories in Reverse Order, and check Axis Crosses at Automatic (Chart 4). Don't worry about the different Y axis scales.
Right click on the quarterly data series in the chart, select Change Series Chart Type, and select the clustered column type (Chart 5). Don't worry that the bars are stalactites instead of stalagmites.
Format the secondary vertical axis (right edge of chart) and check Crosses At Automatic. This moves the quarterly axis and its labels to the bottom of the chart (Chart 6).
Hide the quarterly axis: format it so that it uses no line, and its label position is No Labels (Chart 7).
Delete the secondary vertical axis. Now both series use the primary axis for scaling (Chart 8).
Finally format the bars. I used a gap width of 20% so they each span three months of the line chart. I used a transparency of 25% so the bar fill color wasn't too bold, and so you can see the gridlines behind them. I added data labels to the bars, using the Inside Base position and Category Name instead of Value (Chart 9).