# Margalef Species Richness...

• Mar 2nd 2009, 08:21 AM
nurglespuss
Margalef Species Richness...
Margalef's richness index: (S-1)/ln(n), where S is the number of taxa, and n is the number of individuals.
Hi all, this may seem pretty simple to you all, but I admit that when it comes to numbers I struggle.
Please correct me where I (may) be getting this wrong:

My struggling point is, what is 'ln' I can't seem to find this anywhere (is it simply 1-n?).
• Mar 2nd 2009, 08:53 AM
Laurent
Quote:

Originally Posted by nurglespuss
Margalef's richness index: (S-1)/ln(n), where S is the number of taxa, and n is the number of individuals.
Hi all, this may seem pretty simple to you all, but I admit that when it comes to numbers I struggle.
Please correct me where I (may) be getting this wrong:

My struggling point is, what is 'ln' I can't seem to find this anywhere (is it simply 1-n?).

Hi,
the formula is $\displaystyle \frac{S-1}{\ln n}=\frac{S-1}{\ln(n)}$. The "$\displaystyle \ln$" is a function called the natural logarithm. You can find this function on scientific calculators (usually, it is on the same key as $\displaystyle \exp$).
• Mar 2nd 2009, 09:01 AM
nurglespuss
Ahhhh my brain finally works, its not 1n its ln (log).
Cheers :>

Quote:

Originally Posted by nurglespuss
Margalef's richness index: (S-1)/ln(n), where S is the number of taxa, and n is the number of individuals.
Hi all, this may seem pretty simple to you all, but I admit that when it comes to numbers I struggle.
Please correct me where I (may) be getting this wrong:

My struggling point is, what is 'ln' I can't seem to find this anywhere (is it simply 1-n?).

• Mar 29th 2009, 05:52 PM
Assignment woes
hi all,

I was hoping you could tell me the which button I should be pushing on my calculator for the Margalef species richness index.

I have both the Log and In buttons on my calcualtor

is it correct if I type in S-1/Log(n
or is it S-1/In(n

• Mar 29th 2009, 07:11 PM
mr fantastic
Quote:

hi all,

I was hoping you could tell me the which button I should be pushing on my calculator for the Margalef species richness index.

I have both the Log and In buttons on my calcualtor

is it correct if I type in S-1/Log(n
or is it S-1/In(n