mathematical-typesetting

问题 I have the following formula in LaTeX, based on Fisher's Exact Test. ( NOTE : requires the use of the amsmath package for \binom .) \begin{equation} P(i,j) = \sum_{x=|N(V_i) \cap V_j|}^{\min\{|V_j|, |N(V_i)|} \frac{ \binom{|V_j|}{x} \binom{|V - V_j|}{|N(V_i)| - x}} {\binom{|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: equation with readable text in fraction http://www

问题 I want to plot a label that looks like this in ggplot2 : Value is $\\sigma$, R^{2} = 0.6 where Value is is ordinary font, $\\sigma$ is a Greek lowercase sigma letter and R^{2} = 0.6 appears as an R with a superscript 2 followed by equal sign ( = ) followed by 0.6 . How can this be used in ggplot factor s and in arguments to things like xlab,ylab of R? 回答1: Something like this : g <- ggplot(data=data.frame(x=0,y=0))+geom_point(aes(x=x,y=y)) g+ xlab( expression(paste("Value is ", sigma,",", R^