[Octave-bug-tracker] [bug #49872] Polar plot incorrect

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?49872>

                 Summary: Polar plot incorrect
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Sat 17 Dec 2016 07:14:59 PM UTC
                Category: Plotting
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: Arvind Rao
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.2.0
        Operating System: Microsoft Windows

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Details:

I am using Win 7. I wrote a simple program to plot a cardioid. 

Program is below:

Plot is fine for b=1, 0.75, 0.5. When I change b to 1/3 or 0.25, the plot is
wrong. The smaller lobe is expected to be to the left of the larger lobe
instead of inside it. Plot for 0.25 is attached.


phi = 0:1:359;
phi = phi * 2 * pi / 360;

# b is the parameter which changes the directivity of the mic
# Type            b
# Omnidirectional 1.00
# Sub-Cardioid    0.75
# Cardioid        0.5
# Super-Cardioid  1/3
# Hyper-Cardioid  0.25
# Figure of 8     0

b = 0.25;
# U is the output signal of a first order directional mic
U = b + (1 - b) * cos(phi);
polar (phi, U)





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File Attachments:


-------------------------------------------------------
Date: Sat 17 Dec 2016 07:14:59 PM UTC  Name: hyper_cardioid_plot_bug.pdf 
Size: 7kB   By: None
Plot for 0.25
<http://savannah.gnu.org/bugs/download.php?file_id=39261>

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