cwhmisc (version 5.0)

functions: Functions for testing and other

Description

Functions for testing on equality, exactly or with a tolerance, functions usable as parameters in other functions.

Usage

inrange(x,r)
mod( m, n  )
modS( m, n )
modR( x, y )
one ( x )
onebyx( x )
sqr( x )
powr( a, x )
equal( x, y )
equalFuzzy( x, y, prec=8*.Machine$double.eps, rel=TRUE )
quotmean(x,y)
safeDiv( num, den )
solveQeq(a,b,c)
chsvd(s)

Arguments

m,n,num,den

Integer

a,b,c,prec,x,y

Real

r

Real vactor

rel

Boolean

s

square matrix

Details

mod = m%%n modS : modulo symmetric to 0. modR: modulo for reals, towards negative infinity. zero returns 0.0 on any argument one returns 1.0 on any argument onebyx = 1.0/x sqr = x^2 powr = a^x, with 0^0 := 1, 0^x := 0 equal x == y equalFuzzy One can choose between relative and absolute precision safeDiv Compute quotient, set 0/0 -> 1, and safeguard r/0 <- cMAXREALBY3Q otherwise quotmean Compute quotient of means of non-NA elements of x by y solveQeq Solve the quadratic equation given by the coefficients, return two solutions if a != 0, else one solution, possibly NA inrange Check if x is in the range r chsvd Check for link{svd} to reproduce matrix

Examples

mod((-3:5),4 ) # 1 2 3 0 1 2 3 0 1
modS((-3:5),4) # -3 -2 -1  0  1  2  3  0  1
x <- 200; y <- x + 0.1
equalFuzzy(x,y,0.1*c(10^(-3:0))) # FALSE  TRUE  TRUE  TRUE
equalFuzzy(x,y,0.1*c(10^(-3:0)),FALSE) # FALSE FALSE FALSE  TRUE
safeDiv(0:3,c(0,0:2)) # 1.552518e+231
solveQeq(0,0,1) # NA NA
solveQeq(0,1,0) # 0
solveQeq(0,1,1) # -1
solveQeq(1,0,0) #  0 0
solveQeq(1,0,1) # 0-1i 0+1i
solveQeq(1,1,0) #  -1  0
solveQeq(1,1,1) #  -0.5-0.866025i  -0.5+0.866025i
solveQeq(sample(1:4,1),sample(1:4,1),sample(1:4,1))
  x <- matrix(rnorm(9),3,3)
  s <- svd(x)
  lV(s$d)
  norm(chsvd(s) - x) # 9.4368957e-16