polar-coordinates

I am trying to convert an image from cartesian to polar coordinates. I know how to do it explicitly using for loops, but I am looking for something more compact. I want to do something like: [x y] = size(CartImage); minr = floor(min(x,y)/2); r = linspace(0,minr,minr); phi = linspace(0,2*pi,minr); [r, phi] = ndgrid(r,phi); PolarImage = CartImage(floor(r.*cos(phi)) + minr, floor(r.sin(phi)) + minr); But this obviously doesn't work. Basically I want to be able to index the CartImage on a grid. The polar image would then be defined on the grid. given a matrix M (just a 2d Gaussian for this example

I have a plot in polar coordinates. I used geom_path to connect the points, but I'd like the paths to be straight lines. Here's what I have so far: example <- data.frame(c(5,4,3),c(0.9,1.1,0.6)) colnames(example) <- c("r", "theta") myplot <- ggplot(example, aes(r, theta)) + geom_point(size=3.5) + coord_polar(theta="y", start = 3/2*pi, direction=-1) + scale_x_continuous(breaks=seq(0,max(example$r)), lim=c(0, max(example$r))) + scale_y_continuous(breaks=round(seq(0, 2*pi, by=pi/4),2), expand=c(0,0), lim=c(0,2*pi)) + geom_text(aes(label=rownames(example)), size=4.4, hjust=0.5, vjust=-1) + geom

I want to use polaraxes on the warp object on the half circumference of the polar presentation. Code without polaraxes but with warp close all; clear all; clc; % https://stackoverflow.com/a/7586650/54964 load clown; img = ind2rgb(X,map); [h,w,~] = size(img); s = min(h,w)/2; [rho,theta] = meshgrid(linspace(0,s-1,s), linspace(0,pi)); [x,y] = pol2cart(theta, rho); z = zeros(size(x)); f1=figure(); hax=axes('Parent', f1); imagesc(img, 'Parent', hax); box(hax, 'off'); axis(hax, 'off'); set(hax, 'yTickLabel', []); set(hax, 'xTickLabel', []); % for polar presentation set(hax, 'Ticklength', [0 0]); %

I really like the polar plot of matplotlib and would love to keep working with it (since my data points are given in polar coordinates anyway and my environment is circular). However, in the plot, I would like to add circles of given radii at specific points. Usually, I would do: ax = plt.subplot(111) ax.scatter(data) circle = plt.Circle((0,0), 0.5) ax.add_artist(circle) plt.show() However, in polar coordinates, I cannot use circle, since it assumes rectangular coordinates. Ideas I have come up with are: generating an array of points with constant radial coordinate and an angular coordinate in

Possible Duplicate: Equation-driven smoothly shaded concentric shapes How could I plot a symmetrical heart in R like I plot a circle (using plotrix) or a rectangle? I'd like code for this so that I could actually do it for my self and to be able to generalize this to similar future needs. I've seen even more elaborate plots than this so it's pretty doable, it's just that I lack the knowledge to do it. This is an example of plotting a "parametric equation", i.e. a pairing of two separate equations for x and y that share a common parameter. You can find many common curves and shapes that can be

I have long identifiers and I would like to make a radial plot where ticks are all at different angles. For example, the first tick on the right at 0 degrees should have a 0 degree angle. The one at the top should be 90 degrees. The one at 270 degrees on the left should be 0 degrees. I want it to look reminiscent of a radial dendrogram. Using matplotlib 2.0.2 and python 3.6.2 Is this possible in matplotlib to rotate individual tick labels or add text labels separately? NOTE: I have updated the plot in response to @ImportanceOfBeingErnest below. Setting ax.set_rticks([]) distorts the plot when

I am trying to convert the pixels of an image from x-y coordinate to polar coordinate and I have problem with it, as I want to code the function by myself. Here is the code I did so far: function [ newImage ] = PolarCartRot % read and show the image image= imread('1.jpg'); %%imshow(image); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %change to polar coordinate [x y z]= size(image); r = sqrt(x*x+y*y); theta = atan2(y,x); for i =0:r for j= 0:theta newpixel = [i; j]; newImage(newpixel(1), newpixel(2),:) = image(i,j,:); end end figure; imshow (newImage); Amro It is not