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Plotting Example Fail

5 messages · Timothy D. Legg, William Dunlap, Boris Steipe +1 more

#
Hello,

I am quite new to R and have high expectations for my future with it.

R version 3.0.2 (2013-09-25) -- "Frisbee Sailing"
Copyright (C) 2013 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

I have stepped back to an earlier tutorial and found an odd inconsistency
with one of the examples:

plot(table(rpois(100, 5)), type = "h", col = "red", lwd = 10, main =
"rpois(100, lambda = 5)")

I read the local documentation on the plot command and it's arguments.
decide to modify some values to see how the resulting behavior changes. 
What I didn't expect was that modifying the text string caused the chart
to change greatly.

plot(table(rpois(100, 5)), type = "h", col = "red", lwd = 10, main =
"rpois(100, lambda = 4)")

With the previous line, the columns change values.

plot(table(rpois(100, 5)), type = "h", col = "red", lwd = 10, main = "hello")

This line even adds a 12th column.

I return to plot the original and the output has changed again.   Here are
some screenshots

http://timothylegg.com/R/lambda5_.png
http://timothylegg.com/R/lambda5.png
http://timothylegg.com/R/lambda4.png
http://timothylegg.com/R/hello.png

What am I doing wrong to get inconsistent results like this?  I'm very new
to R and really hoping that this is a misunderstanding on my part.
#
rpois(100, 5) gives a different set of random numbers each time it is
called, so if you want repeatable results compute it once and use its
value in the calls to plot.  E.g.,
   r <- rpois(100, 5)
   plot(table(r), type="h", col="red", lwd=10, main="hello")
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Tue, Nov 24, 2015 at 11:47 AM, Timothy D. Legg <r at timothylegg.com> wrote:
#
... or read about set.seed() and use it.

B.
On Nov 24, 2015, at 2:58 PM, William Dunlap <wdunlap at tibco.com> wrote:

            
#
Thank you for your suggestions.  I am quite grateful to understand that
plotting is reliable and consistent in R.  I had believed that this was
based on a built-in dataset within the R programming language, just as the
New Zealand volcano is.

I look forward to further participation in R as I continue to develop
skills in this arena.

Timothy D. Legg
#
But please spend some time with an R tutorial or two (An Intro to R
ships with R; there are many more on the Web) before you post further
here. Many such elementary confusions and time wasted -- both yours
and ours -- will be avoided if you do so.

Cheers,
Bert


Bert Gunter

"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
   -- Clifford Stoll
On Tue, Nov 24, 2015 at 12:43 PM, Timothy D. Legg <r at timothylegg.com> wrote: