Puzzled - two calculations that give different results

---

@JohnRudnicki wrote:

I have two questions about the attached worksheet:

1. I am trying to calculate two functions in two different ways: One by using a program, the other using the step function. The program gives expected results and  for one of the functions, the step function expression agrees. For the other, it does not. Obviously, I am doing something wrong, but I cannot see what it is - I  thought I set them up in the same way.

2. When I eliminate an argument from the function, that I do not think is used, I get an error with "augument". This is something else I cannot understand.

---

ad 1)

I have not studied the details and so cannot say, why "StateSlip" fails for the first 71 time values with results larger than 10^307. But you can get rid of those erranous values by using the "on error" statement to replace them with NaN's and as you can see the plot of the remaining values seems to look like you expected:

Here you can see up to which value of" t" the function fails

Error tracing leads us to this function call:

ad 2)

As Luc already suspected you forgot to call "Evolve2" instead of "Evolve1". Calling Evolve1 with only five arguments instead of the expected six means that the results are ot values but functions in one argument. These can't be augmented with "T", hence the error message.