Hi Eric,
Thanks, it works. If I want to convert the matrix to the 1-D vector for the
levelplot, should I use the command below? I thought the t() is a reverse
function, but may be not.
values <- layer$z
values.v <- as.vector(t(values))
On Tue, Jan 16, 2018 at 12:36 AM, Eric Berger wrote:
> If
the latest ggplot from github (to be installed with
`devtools:install_github()`) has support for SF objects too, it's a treat!
However, sf is not exactly designed for raster data. Of course you can make
each of your cells be a square polygon, but it's not the most efficient way
for big datasets. Fo
If layer$z is a matrix and you want to reverse the order of the rows, you
can do:
n <- nrow(layer$z)
layer$z <- layer$z[ n:1, ]
HTH,
Eric
On Tue, Jan 16, 2018 at 8:43 AM, lily li wrote:
> Sorry for the emails, I just wanted to have an example.
> layer$z
>
> 1 1 3 4 6 2
> 2 3 4 1 2 9
Sorry for the emails, I just wanted to have an example.
layer$z
1 1 3 4 6 2
2 3 4 1 2 9
1 4 5 2 1 8
How to convert the matrix to layer$z = c(1, 4, 5, 2, 1, 8, 2, 3, 4, 1, 2,
9, 1, 1, 3, 4, 6, 2)?
I think this vector is the order that levelplot can use. Thanks again.
On Mon, Jan 1
Hi Bert,
I think you are correct that I can use levelplot, but I have a question
about converting data. For example, the statement:
levelplot(Z~X*Y), Z is row-wise from the lower left corner to the upper
right corner.
My dataset just have gridded Z data as a txt file (or can be called
matrix?), ho
The projection is UTM zone, but I meant that I don't have coordinates for
each grid cell, rather, I have coordinates for the upper left corner. The
attribute layer is elevation for each grid cell for example, I assume that
I need to create coordinates for the grid cells first? Thanks.
On Mon, Jan
From your description, I am **guessing** that you may not want a "spatial
map" (including projections) at all, but rather something like a level
plot. See ?levelplot in the lattice package for details. Both I am sure
ggplot2 has something similar.
Apologies if I havemisunderstood your intent/speci
Hi Roman,
Thanks for your reply. For the spatial coordinates layer, I just have
coordinates of the upper left corner, numbers of rows and columns of the
spatial map, and grid cell size. How to create a spatial layer of
coordinates from this data? Thanks.
On Mon, Jan 15, 2018 at 3:26 PM, Roman Lu
Also note that there is an R-sig-geo mailing list dedicated to this topic.
You might also like to look at [1] for more on coordinate projections.
[1]
https://www.nceas.ucsb.edu/~frazier/RSpatialGuides/OverviewCoordinateReferenceSystems.pdf
On Mon, 15 Jan 2018, Roman Lu?trik wrote:
You will n
You will need to coerce your data into a "spatial" kind, as implemented in
`sp` or as of late, `sf` packages. You might want to give the vignettes a
whirl before you proceed.
Roughly, you will have to coerce the data to Spatial* (you could go for a
point, raster or grid type, I think) and also spec
Hi users,
I have no clear clue about plotting spatial data. For example, I just have
a table with attribute values of each grid cell, such as elevation. Then I
have coordinates of the upper left corner in UTM, the number of rows and
columns, and grid cell size. How to create spatial plot of elevat
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