scatter

right now I have a 3d scatter plot with peaks that I need to find the volumes for. My data is from an image, so the x- and y- values indicate the pixel positions on the xy-plane, and the z value is the pixel value for each pixel. Here's my scatter plot: scatter3(x,y,z,20,z,'filled') I am trying to find the "volume" of the peaks of the data, like drawn below: I've tried findpeaks() but it gives me many local maxima without the the two prominent peaks that I'm looking for. In addition, I'm really stuck on how to establish the "base" of my peaks, because my data is from a scatter plot. I've also

This is to clarify the question title. Say you have four lists of integers, with which you want to produce a scatter plot: a=[3,7,2,8,12,17] b=[9,4,11,7,6,3] c=[9,3,17,13,10,5] d=[5,1,1,14,5,8] You also have a function, for simplicity f(x)=1/x , that applies to all lists, so that: from __future__ import division a1=[1/i for i in a] b1=[1/i for i in b] c1=[1/i for i in c] d1=[1/i for i in d] My question: how to add a second y axis, knowing that the values returned by the function range from 0.06 to 1.0 , without using any of the a1, b1, c1, d1 lists in the scatter plots? What I am saying is: if

I'm looking for some way in to convert a scatter plot (X vs Y, color normalized by Z) into a 2D "pixel" image. I.e. how can I plot a pixelized image where the pixels are colored according to a third variable? In my case, I have a list of galaxies, each a with sky coordinate (X,Y) and a distance (Z). I want to make a pixelized image of X vs Y, with the pixels color normalized according to Z (e.g. the median Z value for the galaxies in that pixel). I know I could do something like this with hexbin, but I would like to have square pixels, not hexagons. (Something more like what imshow produces).

I created scattergram using the plot() function in R. Is there any possibility to draw on this graph? I would like to add a straight line and get parameters of it, but in my opinion abline() can be inconvenient (I would like to draw many lines and choose one which will be most proper). How can I accomplish this task? Take a look at RStudio and this example: library(manipulate) data = matrix(rnorm(20), ncol = 2) example <- function(data, a, b){ plot(data[,1],data[,2]) abline(a = a, b = b) } manipulate( example(data, a, b), a = slider(-5,5), b = slider(-5,5) ) This will put a new line on the

I am looking for a function to create a so called Beeswarm boxplot. This is very popular plots used in medicine and biology and I was surprised not to find it for MATLAB. Basically the numerical data for each group are splitted to bins and jitter of points depends on number of points in a particular bin. Here is an example done with R using BEESWARM function: Different colors for additional group is very nice feature but it not needed for me now. There is a function on the file exchange called plotSpread that can do these plots: plotSpread({rand(100,1),randn(100,1)}) data = [randn(50,1);randn