Whether you are estimating on the spot or checking a result somebody else gave you, the llama calculator is the quickest way to get from current date, mating date, mod, difference and difference negative to difference value, due date and earliest.
What Is the Llama Calculator?
The llama calculator works out difference value, due date and earliest from current date, mating date, mod, difference and difference negative.
Biological relationships are usually approximations rather than exact laws, so the output is best treated as an estimate with a sensible range around it.
How the Llama Calculation Works
The calculation applies the relationship as published, step by step, so each intermediate value can be checked against the underlying theory.
Keep the units consistent throughout. Mixing a percentage with a proportion is the single most common source of an answer that is out by a factor of a hundred.
Assumptions Worth Knowing
Any relationship used here assumes a constant rate, a representative sample, or a stable population. Real populations rarely meet those conditions for long, so treat the answer as a guide.
Where the inputs are field measurements, a single misread value can shift the result noticeably. Measure carefully and record what you used.
A Worked Example
Working through an example, with current date set to 10, mating date set to 5, mod set to 2, the calculator returns due date of 29,548,800,005, and earliest of 28,684,800,005, and latest of 30,412,800,005. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out difference value?
Enter current date, mating date, mod, difference and difference negative. The calculator then works through the relationship and reports difference value, due date and earliest.
What does the llama actually calculate?
It takes current date, mating date, mod, difference and difference negative and converts them into difference value, due date and earliest using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter current date?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Is the answer exact?
It is as exact as the formula and the inputs allow. The method itself is the standard one for this problem, so the only sources of error are the figures you enter and the precision you ask for.
Why does a small change in one value move the answer so much?
That happens when an output depends on a ratio, because dividing by a small number magnifies any change in it. Check the units first, then check whether the value you entered is in the range the relationship was designed for.