cartesian-coordinates

问题 i have an assignment on sympy and am struggling with the following question: "Prove with the help of Sympy that 4*(x 2 + y 2 -ax) 3 = 27 a 2 (x 2 +y 2 ) 2 can be written using r = 4a*cos(theta/3) 3 ". I have tried to substitute x = r*cos(theta) and y = r*sin(theta) . Then I tried sp.solveset(eq, r) but I only got a very longset of {}, nothing like the given polar equation. Does anyone know how to do this (I can use sympy and numpy)? 回答1: The following code builds the equation from its left

问题 I've been looking for a solution to convert cartesian coordinates (lat, long) that I have to polar coordinates in order to facilitate a simulation that I want to run, but I haven't found any questions or answers here for doing this in R. There are a number of options, including the built in function cart2pol in Matlab, but all of my data are in R and I'd like to continue getting comfortable working in this framework. Question: I have lat/long coordinates from tagging data, and I want to

问题 I've been looking for a solution to convert cartesian coordinates (lat, long) that I have to polar coordinates in order to facilitate a simulation that I want to run, but I haven't found any questions or answers here for doing this in R. There are a number of options, including the built in function cart2pol in Matlab, but all of my data are in R and I'd like to continue getting comfortable working in this framework. Question: I have lat/long coordinates from tagging data, and I want to

问题 I am working on a spatial analysis problem and part of this workflow is to calculate the angle between connected line segments. Each line segment is composed of only two points, and each point has a pair of XY coordinates (Cartesian). Here is the image from GeoGebra. I am always interested in getting a positive angle in 0 to 180 range . However, I get all kind of angles depending on the order of vertices in input line segments. The input data I work with is provided as tuples of coordinates.

问题 I have an image from weather radar which is in polar coordinates (azimuth, range). Normal resizing functions are not working as they presume the image in Cartesian coordinate I guess. From scikit-image etc. How can I resize the image effectively having same ratio and characteristics maintained as we get in Cartesian. Or the only way is to convert to Cartesian and then back ? Original (masked array) displayed using weather lib: Polar Cordinates Contour based: resized the array (and plotted

问题 I'm still implementing a perspective projection for my augmented reality application. I've already asked some questions about the viewport-calculation and other camera stuff, which is explained from Aldream in this thread However, I don't get any useful value at the moment and I think this depends on my calculation of the cartesian coordinate space. I had some different ways to transform latitude,longitude and altitude to a cartesian coordinate space, but nothing of them seems to work

问题 How can we convert Cartesian coordinates (x, y and z) into latitude and longitude (in decimals) in Matlab? Thanks 回答1: As suggested by @H.Munster it seems like the Geodetic Toolbox - File Exchange submission contains what you need. In particular: xyz2ell - Cartesian (x,y,z) to ellipsoidal (lat,long,ht) coordinates [lat,lon,h] = xyz2ell(X,Y,Z) 来源： https://stackoverflow.com/questions/19567140/converting-cartesian-coordinates-to-latitude-longitude

问题 I know about the function sph2cart , but I feel like I must be using it wrong. In a Calculus textbook, I saw that this following spherical equation: ρ = 1 + 1/5*sin(6θ)*sin(5Φ) produces something that looks like this: I wanted to reproduce this in a Matlab graph, so I wrote the following code [q,t] = meshgrid(linspace(0,pi,100),linspace(0,2*pi,100)); rho = 1+1/5*sin(6*t)*sin(5*q); [x,y,z] = sph2cart(t,q,rho); surf(x,y,z) axis square, axis equal And I got the following graph: Why is this

问题 I'm trying to graph x,y coordinates where the window size is 600px by 600px. (0,0) would be in the top left. (300,300) middle of the window. (600,600) would be in the bottom right. I am trying to translate latitude/longitude in radians to pixels and then plotting them. I'm calculating 1px = ? lat by `fabs(lborder+rborder)/600` I calculated lon by taking the top and bottom borders. Then when I want to find a specific position for a specific lat or lon: lat/(previous # calculated above) Problem

问题 I am trying to get the cartesian position and velocity vectors for each propagation step in my orbit. I am using OrbitalPy http://pythonhosted.org/OrbitalPy/ to generate the orbit with classical Keplerian elements. According to the documentation I should be able to get the state vectors (both position and velocity) from class orbital.utilities.StateVector , but I get a Type Error: new () takes exactly 3 arguments (2 given) Here is the code: from scipy.constants import kilo import orbital from