How to make a density plot in python without loss information?
I would like to know how I can make a density plot in python. I'm using the following code plt.hist2d(x[:,1],x[:,2],weights=log(y),bins=100)
where the x values are an array, and y is how much energie there are in the respective pixel (I'm working with galaxies's images, but not fits images). But there is a problem with this code, if I choose a little value of bins, for example 240, I can see well the structures of the galaxy, however distorced. If I choose a bin's value of 3000, the image loss an amount of information, many values of y do not are plotted. I will show the two examples below.
I tried to use plt.imshow but does not work, appears the problem TypeError: Invalid dimensions for image data. The data that I'm working comes from hdf5 files.
I would like to have the possibility to plot the image, with high resolution, to be possible see the structures of the galaxy better. It's possible?
Here is the images:
With the system you describe, you should set the bin size according to the size of the pixel. That way you would have the maximum resolution.
I suspect however, that the maximum number of levels you can represent is 256.
If you would like more resolution, you may have to calculate the image yourself. According to this article, you can save images with up to 32 bit precision in grayscale. That would probably be exaggerating. 16-bit is nice though. This calculation isn't that difficult, and the PIL (Python Imaging Library) has the tools to do the formatting work.
Of course, much depends on the resolution of the data you have available!