viewer: Output intermediate results in iterations

In dahtah/fixedpoints: Iterate mappings and find fixed points

Description

Add a viewer to an iteration, for monitoring progress. Argument "fun" must be a function with at most two arguments. It will be passed the current value and the iteration number. Some default viewing functions are already defined like "print".

Usage

viewer(fun, every = 1, print.iter = FALSE)

Arguments

fun	a viewer function
every	frequency: run every k iteration (default 1, meaning at every iteration)
print.iter	print iteration number

Value

used for side effects

Author(s)

Simon Barthelme

Examples

f <- function(x) x/2
g <- fp(f)
(g+viewer(print))(.1)
# Now print only after 10 iterations
(g+viewer(print,every=10))(3)
# Print iteration number
(g+viewer(print,every=5,TRUE))(3)

# Define custom viewer:
v = function(x) print(x,digits=2)
(g+viewer(v,every=5,TRUE))(3)
v2 = function(x,ind) sprintf("At iteration %i. Current value %.3f",ind,x) %>% print
(g+viewer(v2,every=5))(3)
#You can have multiple viewers, running at different frequencies
v1 = function(x,ind) sprintf("At iteration %i",ind)%>%print
(g+viewer(v1)+viewer(v2,every=5))(3)
#You can also use plotting
x0 <- rnorm(40)
plot(x0)
v <- function(x) points(x,col="grey")
(g+viewer(v))(x0)

dahtah/fixedpoints documentation built on May 14, 2019, 3:25 p.m.