How can I get value of each cells of grid using ArcObject?
Grid was created by
Spatial Analyst -> Distance ->Straight Line
I need to use this values for other operations.
Please, help me!
see http://forums.esri.com/thread.asp?c=93&f=995&t=58550&m=148036#147741
Related
I'm quite beginner at R so I'm struggling with what I've found on google for how to plot species occurrence data points in R (I know how in QGIS but my supervisors want R) and then fill in 10km or 1km grid squares where the species has occurred. The photo shows what I mean but has been produced in DMap rosemarybeetlemap
The main issue I have is that my csv file of records only has alphanumeric Ordnance Survey grid references - can R plot with these or do they need to be split into easting/northings or even decimal latitude/longitude? and if so, how?
Any help is greatly appreciated!
Locations detailed in Ordnance Survey’s National Grid (NGR) format in contrast to using eastings and northings (in metres) splits the Great Britain into lettered grid squares and then defines locations within each lettered grid square. You know but some explanation you'll find here as a beginners guide to finding grid references).
For your main issue following article maybe a solution for a first step Converting (British) National Grid references.
I quoted some info below (credits to mikerspencer and Claudia Vitolo).
There’s no need to write a script from scratch to convert grid references, someone has done it already! There is some legwork to do in getting your NGR coordinates in a format ready for the conversion. The script that follows does just that, taking a csv file as your start and end point.
I am trying to remove the grids on my map. I used several commands for example: plt.grid(), plt.rcParams["axes.grid"] = False but nothing happens, the map produced as is with the grids. Is there any possible way to remove the grids?
Another thing also, how can I make my plot to be smoothed instead of having the data as blocks (see below a sample of the plot).
enter image description here
Please assist in this regard.
Truly appreciate your time.
Thank you.
In R and using the landscapemetrics package, I am wanting to calculate landscape metrics of a raster file that I have that contains different vegetation types. When I import the raster file into R using the stack function, the file contains one layer with multiple levels (see attached image). enter image description here
Subsequently, when I run a function to calculate a landscape metric, or plot the raster, it works with the "Value" level/column (see second image attached). enter image description here. Rather, I want it to calculate the metric over the "Vegetation_Type" level/column directly. However, I do not know how to do this. Currently, when I calculate for example the amount of core area for each vegetation type, it gives me the result in the form of a table that presents "class = 1-7" with the specific core area of that class, rather than "Vegetation_Type = Hummock". I want to have the "class" column with numbers 1-7 to be substituted by the vegetation types (e.g. Hummock, N, K etc.). Is there anyone who knows how to do this who can maybe help me?
Thank you so much in advance, and sorry for the unlogical post. I am still new here and do not really know how to best structure my questions!
Sincerely,
Jasper
The lanscapemetrics package will always use the numeric ID of each class to make sure the output is type stable, i.e, always identical regardless of the input.
But, since the output is simply a tibble, you should be able to just join the information using e.g. dplyr::left_join().
I'm clearly struggling with this problem for a day now and can't seem to find a nice solution to it. I would really appreciate some help and I'm really a novice in R (since last week).
Problem 1:
I have a set CSV representing grid points which I can parse into a data frame (pointname, latitude, longitude).
Eg:
name,latitude,longitude
x0y0,35.9767,-122.605
x1y0,35.9767,-122.594
x2y0,35.9767,-122.583
x0y1,35.9857,-122.605
x1y1,35.9857,-122.594
x2y1,35.9857,-122.583
x0y2,35.9947,-122.605
x1y2,35.9947,-122.594
x2y2,35.9947,-122.583
The points in this file represent the lower left corner and are arranged in row major format, meaning lowest horizontal grid points first. Each point is a certain great circle distance away from its neighbors (1km). I want to create a grid overlay on a map which I've plotted using ggmap.
What I've tried or considered:
map.grid() - this is really not useful to me as I'm not looking for any kind of projection.
geom_vline() and geom_hline(). These look good but I don't have constant x and y intercepts on a plane. Moreover, once I create a grid, I'd like to use the grid to color against a density.
geom_rect() and geom_tile(). These look really promising and may be what I want. But I'm not able to find a good way of working with these.
I'd like to fill these grid boxes later with another parameter. Any suggestions on how I can create such a grid? This may be a trivial question but I don't know a lot of R yet.
Problem 2:
How can I store or hold such a grid so that I given a point (lat,lon), I can quickly get to that grid. In fact my whole back end is in C++ and can directly output the grid name x<n>y<n> directly against a given search point. I somehow am finding it difficult to count such points against grid points so that I can fill grid with a representative color.
I'm not sure if everything of what I'm saying is clear. Please tell me if I've to clarify something.
Also note that I've Googled quite a lot and not found relevant answers although some looked close.
Eg: This, ThisToo
Thanks for the help!
I´m working with different graph algorithms, and for testing, and see the results, i need to visualize the graph.
I´m trying to use graphviz for visualization, but i dont want to use any Layout Engine, just use the real coordinates of the points.
For example: some TSPLIB instances have coordinates like: 1.54400e+04 8.88800e+03
Is this posible? should i use another tool?
Thanks in advance !
Define the nodes like
nodename [pos="2,4!"];
to position them at (x=2|y=4) (the unit is inches).
Try GoogleCharts
http://code.google.com/apis/chart/