To create graphs with a Negative Exponential
(example based on corn embryo lab)
The procedure for making graphs with an exponential axis is similar to other graphs you have made, however there are several modifications that need to be made when entering the data and formatting the axis. These are detailed in bold type.
If the x-axis has exponential data enter the log of the data. You cannot enter the controls (e.g. 0M ABA or 0M GA) as 0 because it doesn't make sense.
(for 0M use -10) - the data for zero will be plotted at -10. Once the graph is printed you can indicate a break in the axis and replace the -10 with zero ABA.
Enter the data for the x-axis - Caution enter the data for the lowest value first
(for 10-8 M enter a -8, for 10-6 enter a -6 etc.)
Enter data to be plotted on the y-axis into one or more columns following the first column. If you have several levels of the second variable (e.g. GA) the data will be organized in a manner similar to an interaction plot.
Graph type: Scatter - select the chart that connects points with straight lines
Source data: When blocking the data make sure you include the column heading. This way the series will be named. The graph that appears at this point will look strange. You will edit it once it is complete.
Chart options: Add labels. (in this example x-axis is Log ABA concentration (M))
Chart location: For ease of editing the graph should be on a New Sheet.
Warning things may look strange at this point
To edit the x- axis - RC on x-axis -- Format axis -- Scale
Min -11 (if the lowest value used was -10)
Max -3 (if the highest value used was -4)
Value y axis crosses at -11 (one value more than the lowest value used)