Graphing in Excel
In order to make a graph, we first have to understand exactly what we want to graph. In this case, we have taken a number of measurements of velocity at 10 evenly-spaced time periods (in seconds). We want to graph the relationship between velocity and time. Therefore, we want to create a graph of velocity vs. time.
We open a Microsoft Excel spreadsheet and insert the data. Notice how the time in seconds correlates directly with the labels on both the columns and the rows in Microsoft Excel. We only need to insert the velocities, because the corresponding seconds are already accounted for in Excel through the numbering. In order to start making a graph, we must simply highlight all of the data by first clicking on the first cell and dragging the mouse to the last cell. Then click on the highlighted Graph Wizard icon (as shown in the illustration below), or click on the insert menu and click on "Chart" to open the chart wizard.
As you can see above, there are many types of graphs that you can choose from. In choosing a type of graph, it is appropriate to choose a graph that best represents the relationship between the sets of data. In this set of data, there are only two categories: velocity and time. Therefore, I chose a line graph as the most appropriate method, because it accurately represents the different velocities at different times. A column graph would have also been a good choice, because it would have compared the various velocities at their respective times. If we were comparing many different sets of data, a pie graph or other form of a graph would have been a better choice.
Notice above how there are also graph subtypes that you can choose from. You can choose from the illustrations, but it is difficult to see exactly how your graph is going to look. This is why it is important to press the "Press and Hold to View Sample" button located just beneath the sub graph illustrations. Below is an example of a sample of what the graph would look like:
It is a good idea to scroll through and look at the samples of the various types of graphs. When you have found a sample that looks good, simply hit the next button to get to step 2 of the chart wizard.
In step 2, the wizard makes sure that it is including all of the data that you want included. In this case, it is a little hard to tell if the values include all of the values we want to include, but you can distinguish an A1, a colon (:), and an A11, with a few dollar signs mixed in. Those should just be ignored for this part. Since we are confident that we highlighted the appropriate amount of fields, and since our data is in columns and the columns button is highlighted, then we can hit next.
Let's Chart Something!
Step 3 of the chart wizard has a bunch of tabs on the top. First it is important to insert the appropriate labels. On the y-axis, we must label the dependent set of values. On the x-axis, we must label the independent set of values. Which value is which? We must ask ourselves the question, do the time readings depend on what velocity the object is going, or do the velocity readings depend on what time it is? Obviously, the second question is the more accurate one. Time is always considered an independent variable, because it cannot be controlled by any outside factors. Also, other readings generally depend on the time that the reading is taken. So in this case, velocity is our dependent variable, and time is our independent variable. Therefore, we label the x-axis with Time (sec), the y-axis with Velocity (m/sec), and the title as Velocity vs. Time.
It is important to include the unit of measure that we are working with, in this case, seconds for Time, and meters per second for velocity, on the respective axes. Also, we always take the label for the y axis without the unit of measure versus the label for the x axis, as shown above.
For the axes tab, you have the option of including or not including the axes simply by selecting or deselecting the x or y Axis by checking or not checking the box respectively. It is best to choose the automatic option for the x axis.
Similarly, there are options that you can choose to include gridlines. You can see the changes as you check or uncheck the options.
These kinds of options are available and can be added or taken away for clarity and professionalism in the graph.
When we are complete with step 3, we click next to get to step 4 of the chart wizard. Then a couple options come up:
We can either include it as an object within the sheet, or we can include it as a new sheet. The example below shows how it looks if we include it as an object within the sheet. This is a good option if you want the data table included next to the graph, as shown below:
If we choose the other option:
Then the graph will be included on another sheet completely, called Chart 1, as seen on the tabs at the bottom of the window below.
Now we have completed a basic graph, which looks professional and is entirely accurate.