Survey123 for ArcGIS version 1.7 introduced support for more advanced mathematical functions, which can be called in the calculation and constraint columns of a survey question. The table below is a summary of the new mathematical functions.
With these newly supported mathematical functions, sophisticated calculations can be applied to answers in a survey. Here are just a few examples of ways that some of these functions can be incorporated into your survey.
Example 1: The area of a circular plot would be quite hard to measure directly, and without these functions you would likely need to rely on estimations or use a calculator. Now, though, the area can be calculated with this expression automatically by Survey123 for ArcGIS.
Example 2: Say you are putting together a vegetation field survey. You want field users to visit a series of sites, each with 5 plots. You do not need them to sample every plot. Instead, you want them to randomly survey 2 plots in each site. The following screenshot illustrates how using the random and round functions you can make survey123 automatically present the plots to visit to the field user.
Looking at the example above closely, you will notice that we use the random function first. This function picks a random number between 0 and 1, which we multiply by 5 to scale the range to five points as needed, then we add point five and round to keep the site number between 1 and 5.
Example 3: I do not intend to describe in detail the next example, but I wanted to share it with you to illustrate the level of complexity that calculations can support. This particular example was generously shared by a Survey123 user during our beta testing for 1.7 and it calculates the water flow within a pipe based on the speed of the water, diameter of the pipe and other variables.
If you want to learn more about how to use Mathematical functions I recommend you have a look at the following:
- Survey123 Mathematical Functions Quick Reference (Help Topic)
- Using Calculations in Survey123 (Video Tutorial)
- Using Calculations in Survey123 (Help Topic)
- Survey123 for ArcGIS XLSForm sample:
- Open Survey123 Connect for ArcGIS
- Go to New Survey and select the Calculations design from the Samples category. This sample includes a mathematical functions category.
Try out our new mathematical functions to make your survey form smarter!