# Making Astronomy Plots with MS Excel

• Getting magnitudes to go from bright (small numbers on top) to faint (large numbers):
• Double-click along the numbers on the axis you want to "flip" and you will get a dialog box labeled "Format Axis."
• select "Scale" from the list at left, and check the box near the bottom labeled "Values in reverse order",
• then click OK.
• Put labels on the plot (title, x-axis label, y-axis label, etc):
• Open the "Formatting Pallete" and select "Chart Options,"
• select "Title" etc from the drag-down menu,
• type your text into the box labeled "".
• Add a second set of data to your existing plot (chart):
• Open the "Formatting Pallete" and select "Chart Data," and click on "Edit,"
• a dialog box labeled "" will appear, click "Add,"
• click the box to the far-right of "X values" and drag across the columns (or rows) you want for the x-axis,
• do the same for the "Y values" and enter a Name if you like, then hit OK.
• Get standard deviation:
• In a blank cell, type "=stdev(x2:x31)" where x is the label of the column you want the data to come from, and 2,31 is the range of rows you want the data to span.
• Move a new chart onto a separate page (for final display?):
• Select the chart and click Chart/MoveChart, then hit the NewSheet button.  It will appear in a new tab (see bottom of excel window to click b/w chart and Sheet1 (data).
• Put error bars on points:
• Double-click on one of the individual data points in your plot. Excel will bring up a "Format Data Series" window with lots of options.
• Click the Error Bars option from the menu at left; you have a window for X error bars (horizontal, on independent variable, not what we want) and for Y error bars (vertical, on our measured value, what we want) -- click whichever you want.
• You've got several ways to choose error bars:
• Fixed value lets you put a same-sized error bar on each point.
• Percentage puts an error bar that is N% of the size of the Y-value (so they get larger as the Y value gets larger).
• Standard deviation and standard error take the sd & sem of the Y values on the plot (not the values that went into making the data points).
• >> Custom allows you to put error bars with different hi/low values. Select the Custom radio button and click SpecifyValue, and a new pop-up box titled CustomErrorBar will appear. The top and bottom entries will make the upward (+) and downward (-) pointing error bars on a Y-value. Use the mouse to select to columns (or rows) you want for the size of the error bar (you can choose the same column for both if you want symmetrical ebars).

Fall 2010, Andy Layden