The following question is inspired by Jun's problem, which resembles some
of my own problems, but goes off on a tangent about applying plot3D from
Karline Soetart.


On Thu, Dec 5, 2013 at 11:52 PM, Bert Gunter <gunter.berton@gene.com> wrote:

>
> Your comment that:
>
> " I can see the critical point here is to find a right function to
> make the prediction. "
>
> is what indicates to me that your "critical point" is that you have
> insufficient knowledge and need help. Feel free to disagree, of
> course.
>

I don't know if it's true for Jun, but it's definitely true for me - I have
insufficient knowledge! I'm out of my depth with surface estimation, but I
have to learn how to do it, one way or the other.

Currently I'm reading the docs for plot3d.

I loaded the package into rstudio and ran some of the examples.  The
image2D example seems to get its data from a data.frame called "volcano"
with a small "v."

imag2D>  nr <- nrow(volcano)

imag2D>  nc <- ncol(volcano)

imag2D>  image2D(volcano, x = 1:nr, y = 1:nc, lighting = TRUE,
imag2D+        main = "volcano", clab = "height, m")



 The objects() command shows a "Volcano" with a big "V."  The small-v and
big-V volcanoes are not the same, because the str command shows:
[69] "mtcars"          "myf"             "n"               "nam"
 [73] "nc"              "nms"             "nr"
"o"
 ...
[117] "V"               "V2"              "Volcano"
"volcx"
[121] "volcy"           "VV"              "Vy"
"w"
[125] "warm.pal"        "weight"          "width"
"wombat"
[129] "x"               "x.at"            "xx"
"xyz.fit"
[133] "y"               "y1"              "y2"
"y3"
[137] "y.at"            "year"            "yy"
"z"
[141] "z0"              "zi"              "z.predict"
"zz"
[145] "zzz"
> str(Volcano)
 num [1:29, 1:21] 100 103 105 108 110 116 120 122 123 118 ...
> str(volcano)
 num [1:87, 1:61] 100 101 102 103 104 105 105 106 107 108 ...


I don't understand how the "volcano" object works well enough to power the
image2D command, but doesn't show up in "objects()".  At first I thought
there was some kind of secret smuggling compartment in memory space, and
"nr" and "nc" and "volcano" were all hidden in that secret place.  But in
fact, "nr" and "nc" show up in "objects()".

So ... I am even less educated than the other newbies on the list, and I'm
following along, and I really don't see how R is doing what it's doing.
Should I be reading the plot3D .pdf textbooks, or should I give up and go
back to some much more basic textbook?

Thanks.

	[[alternative HTML version deleted]]

