In Grasshopper, a solution flows from left to right. At the far left are input values and parameters, and the far right has the output. In between are one or more key processes, and sometimes additional input and output. Let’s take a simple example to help identify the three parts of any algorithm (input, key process, output). The simple addition algorithm includes two numbers (input), the sum (output) and one key process that takes the numbers and gives the result. We will use purple for the input, maroon for the key processes and light blue for the output. We will also group and label the different parts and adhere to organizing the Grasshopper solutions from left to right.

Example 1-2-1: Algorithm to add 2 numbers:

Algorithms may involve intermediate processes. For example, suppose we need to create a circle (output) using a center and a radius (input). Notice that the input is not sufficient because we do not know the plane on which the circle should be created. In this case, we need to generate additional information, namely the plane of the circle. We will call this an intermediate process and use brown color to label it.

Example 1-2-2: Algorithm to create a circle on the XY-Plane from a center and a radius

Some solutions are not written with styles and hence are hard to read and build on. It is very important that you take the time to organize and label your solutions to make them easier to understand, debug and use by others.

Tutorial 1-2-3: Read Existing Algorithms

Given the following definition, write a description of what the algorithm does, identify input, the main process(s) and output, then label and color-code all the parts. Re-write the solution to make it more readable.

Solution

In order to figure out what the algorithm is meant to do, we need to group the input on the left side, and collect the output on the right side, then organize the processes in the order of execution. We then step through the solution from left to right to deduce what it does. We can examine and preview the output in each step.

So, to answer the question, the example of the tutorial is meant to create a circle that is twice as large as another circle that goes through three given points. One of the points is constructed out of its 3 coordinates.