formula - Typesetting LaTeX fraction terms to be larger in an equation

Question

I have the following formula in LaTeX, based on Fisher's Exact Test. (NOTE: requires the use of the amsmath package for inom.)

egin{equation}
    P(i,j) = sum_{x=|N(V_i) cap V_j|}^{min{|V_j|, |N(V_i)|}
    frac{ inom{|V_j|}{x} inom{|V - V_j|}{|N(V_i)| - x}}
    {inom{|V|}{|N(V_i)|}}
end{equation}

This renders the fraction portion with very small, difficult to read text:

I would like my text more readable, as in the following example:

_{(source: plosone.org)}

What trickery can I use to get LaTeX to render my equation similarly?

Answer 1

This may be what you're looking for:

egin{equation}
    P(i,j) = sum_{x=|N(V_i) cap V_j|}^{min{|V_j|, |N(V_i)|} 
    frac{displaystyle inom{|V_j|}{x} inom{|V - V_j|}{|N(V_i)| - x}}
    {displaystyle inom{|V|}{|N(V_i)|}}   
end{equation}

---

Thought it might be good to add a reference:

A Guide to LaTeX2e, Kopka & Daly, 1995
Section 5.5 Fine-Tuning Mathematics
5.5.2 Selecting font size in formulas

In my edition, it's on pp 141-142, but this is out of stock on Amazon. The nearest Internet pointer I can find just now is here