Visualizing geologic information: Graphing and charting geologic data using Deltagraph Pro

Visualizing geologic information is an essential step in developing understanding about the relationships between different asp data and model results.
It is worth considering how your data or results are presented. This is what advertising all about. You must be aware of the effect of presentation on the viewer.

Visualizing information

The practive of visualization has many aspects. For today's lecture, I want to bring to your attention the work of Edward Tufte, a professor at Yale University who has written several books on the visual presentation of information:
"Show data variation, not design variation."
The Visual Display of Quantitative Information
Envisioning Information
Visual Explanations
One of the concepts from Tufte that has influenced me grately is the data/ink ratio. You want to have as much of the ink in your graphic dedicated to the most important data, rather than any design for a plot or graphic.

Chart ducks

One example of the data/ink ratio is that of chart ducks. Many charting programs try to help by prviding design tools that actually are not very helpful. For example, below is a pie chart that shows the distribution of clast types in a Quaternary deposit in the western White Tank Mountains, Arizona:

Note that the 3D effect looks kind of cool, but it is also distracting. What about this one:

Graphing and charting geologic data using Deltagraph Pro

While Microsoft Excel has adequate charting capabilities, there are some plotting tasks that it does not do or not very well. Another program that we have found to be useful is called Deltagraph Pro. This program has two main parts: a data section and then a chart section.
On the Macintosh side of the computers, start up Deltagraph Pro.
Note that it comes up into a page called Untitled#1:Dataview. This page is one inwhich you can put some data to be plotted.

Sediment provenance example

Here are some data from a count of the number of clasts of a given type within a square meter on the piedmont of the White Tank Mountains (what we used in the pie charts above).
CLAST TYPE	O surface	M1b surface
gneiss            39	        43
granites	37	        41
felsic dikes	43	        46
mafic dikes	3	         1
T. volcs	0	        23
soil carbonates	8	         0
vein quartz	8	        14

Copy those data and then paste them into the dataview page in Deltagraph. Place the cursor in the upper left corner of the page so that the labels are in the labels positions for the columns and rows.

BUT, you will note that it does not put things automatically into the proper columns! How annoying. However, you have things there, so it is easier in this case to fix the data by cutting and pasting into separate columns. Make sure that the upper label row has labels in it so that you can get the autolabeling capability to work. Note that you can import excel files so this cutting and pasting business is not necessary.

Let's do some plotting.
1) Click the cursor in the little arrow in the upper left corner of the Dataview window. That will select the data so that it can be plotted correctly.
2) Click in the Data menu and select Chart Gallery. Note that you will have many to choose from. You can limit your choices by turning the different types on and off.
3) Choose pies and then choose choose multiple pies and click ok. You will get a chart view window with your chart in it. You can resize the chart by grabbing the handles (the little black boxes on the sides that appear when the plot is selected). You can also add annotation and graphics by choosing the correct tool from the tool palette on the left.
4) Go back to the dataview by clicking on the view menu and then data and page 1. Note that you can name these pages and plots under this menu, as well as delete or add pages. If you are plotting lots of related data, you might have several different data pages.
5) Select your data again and then chart gallery and try a different type, such as bars and then columns.
6) We want to label this plot a bit, so select it, and then under the chart menu, choose labels->Y and then give the Y axis a label. In this case, it is Number of occurences.
7) Try a few more plots. Note that you can navigate among the charts under the view menu.
8) you can export the plots as pict files which might be useful for some drawing programs, or you can select the plot, and go to Microsoft Word (running at the same tome on the Macintosh), and paste the graphic. Why don't you try it?

Topographic mapping example

I got started with Deltagraph because I found that it handled topographic mapping quite well. We have used the program Deltagraph Pro to contour our data. This program has two advantages: 1) it can contour a set of data with an irregular boundary, enclosing the area of interest with a relatively close fitting polygon, instead of a rectangle, as is common with most contouring programs; and 2) it uses triangle-based terrain modeling (commonly called a Triangular Irregular Network--TIN). This method essentially models the surface as a series of planar, triangular elements, each of which contains three neighboring data points. The points where contour lines intersect the lines between neighboring points are determined by direct, linear interpolation. The contour lines are then determined by connecting those intersections. Because the contour lines are not smoothed, this method provides a basic contour map that honors each data point directly.

We will use an example of some data that were surveyed byt the ASU Geomorphology course that I taught last fall. We ma pped the topography over a terrace riser adjacent to Queen Creek by measuring the Easting, Northing, and Elevation locations of a few hundred points in the landscape with a surveying instrument.
1) Connect up to the public folder on Caliente, PSF640 in the Appleshare PSF zone as guest. You will see a file there called and double-click on the file named QueenCreek.txt. That is a file of data that is the point number, Easting coordinate, Northing coordinate, and Elevation all separated by a tab that I exported (under Save as...) from Excel.
2) Launch DeltaGraph Pro if it is not already running. Under file menu, choose new. Then click on Import under the file menu, choose tab-delimited data, and then find the QueenCreek.txt file and import it.
3) Note that the data are imported into your dataview in Deltagraph with the point numbers in the A column. Start by labeling the columns appropriately.
4) We need to have the point numbers in the labels column so that they can be plotted appropriately. Select columns A-D by clicking on the letters A through D at the top of the columns. Then choose Cut under the edit menu. Move the cursor to the upper left most cell in the labels row and column and paste. Now the labels should be still correct in their rows, but the point numbers will be in the labels column.
5) Click the cursor in the little arrow in the upper left corner of the Dataview window. That will select the data so that it can be plotted correctly.
6) Click in the Data menu and select Chart Gallery. Note that you will have many to choose from. You can limit your choices by turning the different types on and off. MAKE SURE TO USE THE 2D PLOTS. The 3D will let you make a cool view of the site, but it is not what you want. This time display contours and choose XYZ countours. DO NOT USE the regular contours plot. It will not work very well. You can see which is which by moving the mouse over the icon without clicking, and you will see the name of the plot type displayed below in the Chart Gallery dialogue box. The push ok, and wait for the contour plot to show up!
7) Click on the plot and then go to the Chart menu and add the appropriate labels for the axes, change the label interval, etc.
8) Very importantly, the horizontal scales should be the same. Note that Deltagraph Pro makes the plot square by default, but the map is actually not. Make a note of the number of meters in the Easting direction and in the Northing direction. Go to the Chart menu and choose Set All... Then Choose Xaxis. Note that you can change the axis label intervals and so on. Click on axis attributes and choose an appropriate scaling (such as 1 cm = 10 m) for the length of the axis. Do the same for the y axis. If you want to change the contour interval, select the z axis and change the interval.
9) To show symbols, click on the chart, go to options under the chart menu, and then select show symbols. If the points are too big (data/ink ratio a bit low), under the chart menu, choose symbols, and pick a smaller symbol as well as smaller font size. To show the point numbers (the symbols have to be shown first), choose Show values under the chart menu and then choose the orientation of the point label, as well as category for the type. That will display the point number. If you want to show the spot elevations, then choose value instead of category.

Pages maintained by
Prof. Ramón Arrowsmith

Pages last modified on Tues Oct 7 1997.