graypolarplot Polar 2D plot of a surface using colors

## Syntax

    graypolarplot(theta,rho,z,[strf,rect])

## Arguments

theta

  a vector with size n1, the discretization of the the angle in radian.

rho

  a vector with size n2, the discretization of the radius

z

  real matrix of size (n1,n2). `z(i,j)` is the value of the surface at the point (theta(i),rho(j)).

strf

  is a string of length 3 `"xy0"`.

  default

    The default is `"030"`.

  x

    controls the display of captions.

    x=0

      no captions.

    x=1

      captions are displayed. They are given by the optional argument `leg`.

  y

    controls the computation of the frame.

    y=0

      the current boundaries (set by a previous call to another high level plotting function) are used. Useful when superposing multiple plots.

    y=1

      the optional argument `rect` is used to specify the boundaries of the plot.

    y=2

      the boundaries of the plot are computed using min and max values of `x` and `y`.

    y=3

      like `y=1` but produces isoview scaling.

    y=4

      like `y=2` but produces isoview scaling.

    y=5

      like `y=1` but `plot2d` can change the boundaries of the plot and the ticks of the axes to produce pretty graduations. When the zoom button is activated, this mode is used.

    y=6

      like `y=2` but `plot2d` can change the boundaries of the plot and the ticks of the axes to produce pretty graduations. When the zoom button is activated, this mode is used.

    y=7

      like `y=5` but the scale of the new plot is merged with the current scale.

    y=8

      like `y=6` but the scale of the new plot is merged with the current scale.

leg

  a string. It is used when the first character x of argument `strf` is 1. `leg` has the form `"leg1@leg2@...."` where `leg1`, `leg2`, etc. are respectively the captions of the first curve, of the second curve, etc. The default is `""`.

rect

  This argument is used when the second character y of argument `strf` is 1, 3 or 5. It is a row vector of size 4 and gives the dimension of the frame: `rect=[xmin,ymin,xmax,ymax]`.

## Description

Takes a 2D plot of the surface given by `z` on a polar coordinate grid defined by `rho` and `theta`. Each grid region if filled with a gray or color level depending on the average value of `z` on the corners of the grid.

## Examples

    rho=1:0.1:4;theta=(0:0.02:1)*2*%pi;
    z=30+round(theta'*(1+rho.^2));
    f=gcf();
    f.color_map= hot(128);
    clf();graypolarplot(theta,rho,z)

rho=1:0.1:4;theta=(0:0.02:1)*2*%pi; z=30+round(theta'*(1+rho.^2)); f=gcf(); f.color_map= hot(128); graypolarplot(theta,rho,z)