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persp fail with non-equidistant dates

2 messages · Tomas Bayer, Duncan Murdoch

Original
Tomas Bayer
# 
Hello,
when I plotted non-equidistant data in 3D (using persp and contour), it
was ended with the same error message:
main="Altitude")
Error in persp.default(y, x, z, xlab = "latitude", ylab = "longitude",  :
  increasing 'x' and 'y' values expected

How to fix it? The original data are in columns

 50.84925    14.65715 614.0  48909.14   -62.49  99  48929  5  122306
 50.84919    14.65702 617.0  48816.32  -145.82  69  48836  6  122331
 50.84908    14.65681 622.0  49113.40     6.64  99  49133  4  122442

Tomas Bayer
  ,           ,
 /             \
((__-^^-,-^^-__))
 `-_---' `---_-'
  `--|o` 'o|--'
     \  `  /
      ): :(
      :o_o:
       "-"
GNU's Not Unix!
Duncan Murdoch
#
On 22/08/2016 11:17 AM, Tomas Bayer wrote:
You haven't shown us what is in y, x and z, but it looks as though you 
haven't got data in the form required by persp, i.e. a vector of 
increasing values in each of the first two arguments, and a matrix of 
values in the third.  Using your variable names, you'd want z[i,j] to 
correspond to y[i] and x[j].

If you just have a collection of (y, x, z) triples, you'll need to do 
some pre-processing to fit a surface and produce the required inputs.

Duncan Murdoch