precision problem
Omar Lakkis wrote:
I have prices that I am finding difficult to compare with ==, > and >, due to precision. For example: the numbers should match, with '==', but they differ in the magnitude of 1e-14 due to bunch of calculations that I run on them. Programming with java, I am used to implementing a function that compares the difference between the numbers to a pre determined precision factor. This could be very slow when I have two matrices of numbers that I could otherwise compare with a simple '==', '>' or '<' in R. What is teh best solution for this problem? Can I control the precision of ==, > and < without having to reimplement the operations in a slow way?
The somewhat misleadingly named "all.equal()" function does what you want for ==. For the inequalities, you may want to add some constant to one side, e.g. x > y-.Machine$double.eps ^ 0.5 instead of x > y. Duncan Murdoch