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I know this is a very wide subject - still - I would like to convert a GIS DMS coordinates, for example:
33° 0' 10'' , 33° 40' 30''
into an EPSG:3857 format, ie:
3689865.02422557637, 3212878.5986975324
(this is not the calcualated convert, just an exmaple of the formats).
I know there are calculations\conversions in Map suppliers (ESRI, etc.). I'm looking for either of these ways, if somehow possible:
nodejs module (proj4js ? I looked in it but couldn't find a way doing so).
asp.net core FW feature\nuget ?
Yeah, proj4js can do this. First convert your DMS coordinates into decimal degrees, then tell proj4js to convert from WGS-84 to EPSG:3857.
Happily, proj4js ships with this conversion, so you don't have to look for the datum strings online.
const proj4= require("proj4");
// TODO: that's not the correct conversion of the original DMS to decimal degrees :)
console.log(proj4("WGS84", "EPSG:3857", [33.01, 33.4]));
outputs
[ 3674656.3910859604, 3948518.4270993923 ]
I have highlighted specific activities (feeding,resting and sleeping) from the dataset in my plot. Now I want to connect these highlighted points in sequence over my polar coordinates.
Here's my dataset:
Activity Latitude Longitude
Feeding 21.09542 71.06014
Resting 21.09564 71.06064
Sleeping 21.09619 71.06128
Walking 21.09636 71.06242
Walking 21.09667 71.06564
Resting 21.09483 71.06619
Can you help me out in this?
# Example dataframe
set.seed(1)
mydf=data.frame(Activity=sample(c("Walking","Feeding","Resting","Sleeping"),20,T),Latitude=rnorm(20,21,0.5),Longitude=rnorm(20,71,0.5))
mydf$Order=1:nrow(mydf)
If you want to connect the points in order regardless of the activity, do the following (for clarity, I added the variable mydf$Order to label the points).
# Plot
library(ggplot2)
ggplot(data=mydf)+
geom_point(aes(x=Latitude,y=Longitude,colour=Activity))+
geom_path(aes(x=Latitude,y=Longitude))+
geom_text(aes(x=Latitude,y=Longitude,label=Order))+
coord_polar(theta="y")
If you want to connect points according to activities, consider CMichael's answer.
Ok I am starting from scratch: My original answerwas much too bulky and inflexible.
Just add the following to get Paths for each Activity without filtering.
+ geom_path(aes(colour=ACTIVITY,x=Latitude,y=Longitude))
If you want to plot only selected Activities:
+ geom_path(data=Data[Data$ACTIVITY %in% c("Sleeping","Resting"),],aes(colour=ACTIVITY,x=Latitude,y=Longitude))
The selected Activities are to be listed in the c(...) vector with each name quoted.
UPDATE: OP clarified that he wants to connect any stationary point, this achieved by running the following:
+ geom_path(data=Data[Data$ACTIVITY!="Walking",],colour="red",aes(x=Latitude,y=Longitude))
Note that the colour=ACTIVITY is removed from the aesthetics and we consider all stationary points (!="Walking") to draw the path.
Code combining the two answers:
set.seed(1)
mydf=data.frame(Activity=sample(c("Walking","Walking","Walking","Walking","Walking","Resting","Feeding","Sleeping"),20,T),Latitude=rnorm(20,21,0.5),Longitude=rnorm(20,71,0.5))
mydf$Order=1:nrow(mydf)
# Plot
library(ggplot2)
ggplot(data=mydf)+
geom_point(aes(x=Latitude,y=Longitude,colour=Activity),size=5)+
geom_path(aes(x=Latitude,y=Longitude),size=1.2)+
geom_text(aes(x=Latitude,y=Longitude,label=Order))+
geom_path(data=mydf[mydf$Activity!="Walking",],colour="red",aes(x=Latitude,y=Longitude)) +
coord_polar(theta="y")
I am trying to write a Matlab script to analyze two specific sets of data, create histograms for them, and write them to a single file where you can see both histograms overlapped on one plot.
I created a functioning script that created the histogram for 1 set of data that basically went like this:
h1=figure;
hist(data,nbins:;
print(h1,'-dpng','hist.png)
Then I tried to simply add a second line of:
h2=figure;
and changed the print function to include h2. That obviously didn't work. I found that I couldn't have both an h1 and an h2 with the print function.
After searching the internet and looking for ways to get around this I decided to try to use saveas instead. I got to the following:
h=findobj(gca,'Type','patch');
hist(data1,nbins);
hold on;
hist(data2,nbins);
set(h(1),'FaceColor','r','EdgeColor','k');
set(h(2),'FaceColor','b','EdgeColor','k');
saveas(h,'-dpng','hist.png')
But this won't quite work either. I haven't found anything on the Mathworks website that helps me with this problem, and I haven't found anything on any other site either. I am using a Linux computer connecting to a different server via SSH so the only way that I can view plots that I make is by saving them to a file and then opening them. Please let me know if you have any suggestions to accomplish my task as outlined in my first paragraph. Thank you.
One way is to use different axes for different histogram. You can use SUBPLOT for this:
subplot(2,1,1)
hist(data1,nbins);
subplot(2,1,2)
hist(data2,nbins);
Another way is to find a common bins (x) and return the hist output to vectors. Then use BAR function for the plot.
nbins = 20;
x = linspace(min([data1(:);data2(:)]),max([data1(:);data2(:)]),nbins);
h1 = hist(data1, x);
h2 = hist(data2, x);
hb = bar(x,[h1(:),h2(:)],'hist');
% change colors and set x limits
set(hb(1),'FaceColor','r','EdgeColor','k');
set(hb(2),'FaceColor','b','EdgeColor','k');
gap = x(2)-x(1);
xlim([x(1)-gap x(end)+gap])
Anyone know how to convert latitude, longitude in degrees to define a BBOX where SRS=EPSG:27700?
I am trying to call a WMS service with a URL like following (not a real link):
http://mysecretmappingserver.com/wms?user=myuser&pwd=mypassword&VERSION=1.1.1&REQUEST=GetMap&LAYERS=ap25cm&STYLES=&SRS=EPSG:27700&BBOX=229096,231675,229296,231875&width=400&height=400
Any language would be fine; C# preferable.
Spacedman has been trying to help me, but I can't seem to get Proj4Net to work for me - all me, I'm sure - but if someone knows either Proj4Net or the math involved, that might be better...
You need an interface to the PROJ.4 projections library in your language of choice. In R, for example, its in the rgdal package:
Here's some points (1,1 to 2,2 degrees) in epsg:4326:
> pts
SpatialPoints:
coords.x1 coords.x2
[1,] 1 1
[2,] 2 2
Coordinate Reference System (CRS) arguments: +init=epsg:4326
and voila:
> spTransform(pts,CRS("+init=epsg:27700"))
SpatialPoints:
coords.x1 coords.x2
[1,] 734005.9 -5416918
[2,] 845270.7 -5305999
Coordinate Reference System (CRS) arguments: +init=epsg:27700
Proj.4 docs here:
http://trac.osgeo.org/proj/
Since this is OSGB, probably a better example would be in the UK: here's a point in central london:
> pts = SpatialPoints(cbind(-0.109863,51.460852),proj4string=CRS("+init=epsg:4326"))
> spTransform(pts,CRS("+init=epsg:27700"))SpatialPoints:
coords.x1 coords.x2
[1,] 531407.1 175235.8
Coordinate Reference System (CRS) arguments: +init=epsg:27700
+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000
+y_0=-100000 +ellps=airy +datum=OSGB36 +units=m +no_defs
+towgs84=446.448,-125.157,542.060,0.1502,0.2470,0.8421,-20.4894
I recommend ogr2ogr, which among other things can convert between projections. I have it installed on my Mac, and there are binding e.g. to Python and many other languages. You can also use it on the commandline. Homepage is http://www.gdal.org/ogr2ogr.html
This question kind of starts where this question ends up. MATLAB has a powerful and flexible image display system which lets you use the imshow and plot commands to display complex images and then save the result. For example:
im = imread('image.tif');
f = figure, imshow(im, 'Border', 'tight');
rectangle('Position', [100, 100, 10, 10]);
print(f, '-r80', '-dtiff', 'image2.tif');
This works great.
The problem is that if you are doing a lot of image processing, it starts to be real drag to show every image you create - you mostly want to just save them. I know I could start directly writing to an image and then saving the result. But using plot/rectangle/imshow is so easy, so I'm hoping there is a command that can let me call plot, imshow etc, not display the results and then save what would have been displayed. Anyone know any quick solutions for this?
Alternatively, a quick way to put a spline onto a bitmap might work...
When you create the figure you set the Visibile property to Off.
f = figure('visible','off')
Which in your case would be
im = imread('image.tif');
f = figure('visible','off'), imshow(im, 'Border', 'tight');
rectangle('Position', [100, 100, 10, 10]);
print(f, '-r80', '-dtiff', 'image2.tif');
And if you want to view it again you can do
set(f,'visible','on')
The simple answer to your question is given by Bessi and Mr Fooz: set the 'Visible' setting for the figure to 'off'. Although it's very easy to use commands like IMSHOW and PRINT to generate figures, I'll summarize why I think it's not necessarily the best option:
As illustrated by Mr Fooz's answer, there are many other factors that come into play when trying to save figures as images. The type of output you get is going to be dependent on many figure and axes settings, thus increasing the likelihood that you will not get the output you want. This could be especially problematic if you have your figures set to be invisible, since you won't notice some discrepancy that could be caused by a change in a default setting for the figure or axes. In short, your output becomes highly sensitive to a number of settings that you would then have to add to your code to control your output, as Mr Fooz's example shows.
Even if you're not viewing the figures as they are made, you're still probably making MATLAB do more work than is really necessary. Graphics objects are still created, even if they are not rendered. If speed is a concern, generating images from figures doesn't seem like the ideal solution.
My suggestion is to actually modify the image data directly and save it using IMWRITE. It may not be as easy as using IMSHOW and other plotting solutions, but I think it is more efficient and gives more robust and consistent results that are not as sensitive to various plot settings. For the example you give, I believe the alternative code for creating a black rectangle would look something like this:
im = imread('image.tif');
[r,c,d] = size(im);
x0 = 100;
y0 = 100;
w = 10;
h = 10;
x = [x0:x0+w x0*ones(1,h+1) x0:x0+w (x0+w)*ones(1,h+1)];
y = [y0*ones(1,w+1) y0:y0+h (y0+h)*ones(1,w+1) y0:y0+h];
index = sub2ind([r c],y,x);
im(index) = 0;
im(index+r*c) = 0;
im(index+2*r*c) = 0;
imwrite(im,'image2.tif');
I'm expanding on Bessi's solution here a bit. I've found that it's very helpful to know how to have the image take up the whole figure and to be able to tightly control the output image size.
% prevent the figure window from appearing at all
f = figure('visible','off');
% alternative way of hiding an existing figure
set(f, 'visible','off'); % can use the GCF function instead
% If you start getting odd error messages or blank images,
% add in a DRAWNOW call. Sometimes it helps fix rendering
% bugs, especially in long-running scripts on Linux.
%drawnow;
% optional: have the axes take up the whole figure
subplot('position', [0 0 1 1]);
% show the image and rectangle
im = imread('peppers.png');
imshow(im, 'border','tight');
rectangle('Position', [100, 100, 10, 10]);
% Save the image, controlling exactly the output
% image size (in this case, making it equal to
% the input's).
[H,W,D] = size(im);
dpi = 100;
set(f, 'paperposition', [0 0 W/dpi H/dpi]);
set(f, 'papersize', [W/dpi H/dpi]);
print(f, sprintf('-r%d',dpi), '-dtiff', 'image2.tif');
If you'd like to render the figure to a matrix, type "help #avifile/addframe", then extract the subfunction called "getFrameForFigure". It's a Mathworks-supplied function that uses some (currently) undocumented ways of extracting data from figure.
Here is a completely different answer:
If you want an image file out, why not just save the image instead of the entire figure?
im = magic(10)
imwrite(im/max(im(:)),'magic.jpg')
Then prove that it worked.
imshow('magic.jpg')
This can be done for indexed and RGB also for different output formats.
You could use -noFigureWindows to disable all figures.