Graphing Data

1
Graphing Data

• Excel Charts

2
Excel Charts. Create the data table.

• First step is to create the data table
• Enter the column headings and the first two time
  values
• To continue the time sequence for 0 to 3 secs
• drag select the first two entries
• move the cursor to the replication tab
• click and drag until the last entry is 3 secs
• Enter the formula for an exponential process that
  begins at 5 volts and decays with a time constant
  of 0.5.
• Replicate the formula for the other time instants
• Format the cells to have 1 fractional digit for
  the time values and 2 for the voltages. Center
  both columns.

3
Excel Charts. Create the chart.

• To create the chart (graph), drag select the data
• Click on the Chart Wizard toolbar icon.
• Select the XY (Scatter) type of plot where only
  the points are plotted.
• Click Nextgt to bring up the Source Data
  dialog. Here, you can
• change the data selection
• indicate that the data is organized in rowson the
  Series pane, add data sets
• assign a name to the data set for the plot legend
• Click Nextgt to get the Chart Options dialog.
• gridlines(show major on both axes),
• legend (hide it)
• Click Nextgt to get the Chart Location dialog

4
Excel Charts. Format

• End result is an embedded chart.
• Drag the corners of the Chart Area to resize
  and reposition the plot
• All of the decisions that were made in creating
  the plot can be changed by right-clicking on the
  chart area and selecting from the resulting popup
  menu.
• Right-clicking on any of the plot elements brings
  up an appropriate popup context menu
• Format Plot Area...
• Format Axis...
• Format Axis Title...
• Format Data Series...
• Right-click on the plot area and select the
  Chart Location item
• Place the plot on its on sheet.

5
Excel Charts. Add data to the chart.

• Create a new column for the voltage variation
  with a time constant of 0.2
• Drag select the time and voltage columns - to
  select two nonadjacent columns
• drag-select first column,
• press and hold the CTRL key, and
• drag-select the second column.
• Right click on the selected data and select
  Copy
• Select the plot sheet, click on the plot area,
  and select Paste Special from the Edit menu.
• Indicate that this is a new data series (data
  set), the data is arranged in columns, and the X
  values are in the first column.
• Clean up the formatting and add a legend.

6
Excel Charts. Create a plot with 2 data sets.

• Could also plot both data sets from the beginning
  of the process.
• Drag-select the time column with both columns of
  voltage data.
• Repeat the plot creation process but allow the
  inclusion of a legend on this plot.
• After formatting both curves are generated and
  the column headings are used as the descriptions
  in the legend.

7
Excel Charts. Logarithmic plots.

• Using a logarithmic vertical axis should yield a
  linear plot of the exponential process.
• Select format axis for the Y Axis
• Select Logarithmic Axis and allow the Auto
  choice for the major unit selection on the
  Format Axis Dialog
• Need to revise the number formatting and scale on
  the logarithmic axis to cover three cycles, 0.001
  to 10.
• Force the labels on the X axis tic marks to
  appear at the bottom of the plot.