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IF LOOOP

4 messages · matthias worni, Rolf Turner, David Winsemius +1 more

matthias worni
# 
Hey

This should be a rather simple quesiton for some of you. I want to make
some progress in looping...
I have the vector r, which contains single values --> see below:

r
  [1] 1.1717118 1.1605215 1.1522907 1.1422830 1.1065277 1.1165451 1.1163768
1.1048872 1.0848836 1.0627211
 [11] 1.0300964 1.0296879 1.0308194 1.0518188 1.0657229 1.0685514 1.0914881
1.1042577 1.1039351 1.0880163


I would like to take out simply the value "0.990956" from the vector,
printing out the rest of it.  The code is from the internet but does not
seem to work for my vector. Can't figure out why... Thanks for the help

r <- as.vector(lw)
count=0
for (i in r)  {
  if(i == 0.990956) {
    break
  }
    print(i)
  }


Best
Matthias
Rolf Turner
#
On 14/06/17 08:46, matthias worni wrote:
FAQ 7.31

cheers,

Rolf Turner
David Winsemius
# 
I'm not sure that the source of this code should be considered a trusted foundation for learning R. You should not be using for-loops to modify vectors in this manner.
That's probably not needed.
I suspect you meant to use:

?'next'   # since `break` completely terminates a for-loop.


The ?'help' page has all the "control structures": `for`, `repeat`, `while` and associated boundaries and terminators

Both `break` and `next` are reserved words (names of functions, control tokens), so using the `?` operator requires quoting.

Also that for-next loop would do _nothing_ to the value of r. Printing would not modify the value of `r`.

You should read:

?Reserved

?'for'  # since `for` is also reserved

?print
After following Rolf's advice ... Try:

r[ all.equal(r, 0.990956) ]
Further note to matthias:
All caps in Subject is considered poor form, as is posting in HTML.
Jim Lemon
# 
Hi Matthias.
The first thing I notice is that the vector r:

r<-c(1.1717118,1.1605215,1.1522907,1.1422830,1.1065277,1.1165451,
 1.1163768,1.1048872,1.0848836,1.0627211,1.0300964,1.0296879,
 1.0308194,1.0518188,1.0657229,1.0685514,1.0914881,1.1042577,
 1.1039351,1.0880163)

doesn't contain the value 0.990956. If it ain't there, you can't
remove it. It has already been suggested that the failure of any
explicit value like 0.990956 to equal its displayed representation is
due to machine precision. I'll guess that you really want to remove a
range of values, something like those less than 1.000000. If so, try
this:

r[r>=1]

Jim
On Wed, Jun 14, 2017 at 6:46 AM, matthias worni <mat.worni at gmail.com> wrote: