Zoom and polar axes

__Hi guys. I have MATLAB 2017a and I've faced the problem, that zoom doesn't work with polar axes. I've met another one question with the same problem in R2016B version of MATLAB.

__1. Is there any way use ZOOM with polar axes?

__2. Does it work well in newer versions of MATLAB?

[hai du]

do you think there's a bug on the rlim on this polatplor?

[Adam Danz]

@hai du could you be more specific?

rlim behaves a bit oddly, thought by design, when the minimum limit is <0, if that's what you're running into.

Answer 1

[Adam Danz]

The zoom() feauture seems to be disabled on polaraxes.

You could use set rlim() and thetalim() to zoom into a specific area.

The Antenna Toolbox offers a polarpattern class that does allow for zooming and other interactions but it doesn't technically use a polaraxes.

[TARAM]

__I checked, that polarpattern function allows to use data cursors. But there is a next problem. As far as i understood, it is not possible to draw temperature plot using polarpattern class. Polar R (distance) in this case is spherical Theta angle, polar Phi - is spherical Phi. Color of current point is proportional to spherical R.

__The only way to do it, as i see, is to use simple Axes object and use contourf to draw temperature plot. I have to draw polar and radial axis's and number's by myself, and i need to write my own text update function (to display Theta, Phi and Level data instead of rectangular X,Y,Level).

[Adam Danz]

What function are you using (or would you like to use) to create the temperature plot?

If you plot polar data on cartesian coordinates, you can use pol2cart() or sph2cart() to convert your polar inputs to cartesian. Drawing the circular radii and radian thetas would only take a few lines of code and you would not need to write a text update function to lable the thetha ticks.

Just be sure all of that time investment will be worth it instead of just setting rlim() and thetalim() on the polaraxes. Note that it would take less time to just add a couple slider objects to your polaraxes figure that control these limits.

[TARAM]

"What function are you using (or would you like to use) to create the temperature plot? "

__I wanted to make temperature plot of antenna array pattern. Pattern is narrow, so, of course, i need ZOOM tool. I solved similar problem few years ago. At that time i drawed everything (lines, tick numbers etc) by myself in rectangular coordiantes. I hoped matlab developers thinked up something to do it faster and more conveniently in REAL polar coordinates.

"you would not need to write a text update function to lable the thetha ticks"

__I mean't, text update function of data cursor to display polar coordinates instead of rectangular (i plotted data using last ).

[Adam Danz]

I agree that we need to have zoom with polaraxes.

This may or may not help but you could try playing around with rlim() and thetalim() to see if you can zoom into the data. If that works, it would be much simpler to add a couple sliders into your figure so you can interactively zoom into rho and theta areas.

Here's a demo.

% Generate tightly clustered dots
y = rand(1,500)+2; 
x = rand(size(y))./4; 
[th,rh] = cart2pol(x,y); 

pax = polaraxes(); 
polarplot(th,rh,'.')

% zoom into the theta range
thetalim([80,95])

% Zoom into the rho range
rlim([1.5,3.1])