I am so busy that I have no time to write on my blog lately (soon things will go back to normal with more frequent longer posts…). However, I still try to post stuff once in a while. And, lately, I have decided to post stuff that I find particularly useful for what I do. Today is the turn for two Excel tricks I just learned. As usual, I am not reinventing the wheel (many of my readers might already know both tricks), but these are things that could be very useful at some point.

  • How to divide Excel cells by a number

This is the test case. You generated tons of data of, say, throughput in bps. Many many cells full of big numbers. But, when it comes to the time to generate a nice plot for a paper or a report, you want things in, for example, Mbps. How would you divide all those values by a given scaling factor (10^6 to go from bps to Mbps)?

One option would be to make an empty cell “=cell_with_data_in_bps/1000000” and apply to as many empty cells as cells with data you have. This way, though, requires twice as much “space” in your spreadsheet.

The way to do it is as follows. You write 1000000 on any empty cell. Select that cell and copy it (Ctrl+C). Then mark all the cells you want to modify. Right-click and select paste special. On “Operation” select “divide” and accept. Voila! Problem solved. And note that you can do the same with adding, subtracting or multiplying.

  • How to add a second Y-axis to an Excel plot

What about when you want to plot two types of data on a figure but they are on different scales? Plot everything. Then right click on a data series you want to modify, right-click and choose “Format data series”. In “Series options” select secondary axis. From here the rest should be piece of cake.