Issue #18: Analyse the function integralEvaluation

README.md

@@ -41,6 +41,14 @@ This function is more complex than it needs to be. It uses a `switch-case` state
 
 CCN  =  E - N + 2  =  38 - 23 + 2  =  17
 
+### Function SimpsonIntegration.integralEvaluation
+
+For the function integralEvaluation in Maths/SimpsonIntegration.js, lizard calculated its cyclomatic complexity as 15. When analysing the function by hand, I constructed a control flow graph with 37 edges and 24 nodes. Using the formula E - N + 2, the by-hand cyclomatic complexity was also calculated as 15. It seems lizard does account for exceptions, as while constructing my control flow diagram, I drew edges from where the exceptions were thrown to the return node at the bottom. If these are not counted, the cyclomatic complexity is significantly lower.
+
+The purpose of the function is to approximate the value of a definite integral, using Simpsons 1/3 rule. This function was one of the ones with the highest cyclomatic complexity in the repository, but its number of lines of code (26) is not particularly large. A large part of the cyclomatic complexity seems to be comming from the quite extensive input validation.
+
+The documentation of the function is quite thorough. There is a comment above the function, explaining what the function does, as well as the requirements of the different parameters. There are also comments inside the function, explaning what different parts are supposed to do. When the function throws an error, it is clearly specified by the error message what went wrong. There is extensive error checking for the input, however, I noticed that there is no check to make sure that the passed variable "func" is indeed a function. If it is not, an error will be thrown when the "func"-variable is attemped to be invoked.
+
 #### Function `FlashSort.flashSort` (58 NLOC, 15 CCN):
 
 The purpose of this function is to efficiently sort an array of numerical values. Input is an array consisting of `n` number of elements. Output is an array consisting of the same `n` number of elements sorted in ascending order.