The peak wave direction categories (degrees clockwise from True North):

• 11.25 - 33.75 (centered at 22.5)
• 33.75 - 56.25 (centered at 45.0)
• 56.25 - 78.75 (centered at 67.5)
• ...
• 349.0 - 11.5 (centered at 0.0)

The color coded significant wave height categories (meters):

• 0-1
• 1-2
• ...
• 9-10

Source Code:

%-----------------------------------------------------------------------
% Name:
%   .dbase/web_programs/plotpro/matlab_scripts/wave_rose.m
% Description:
%   Creates a wind_rose plot by calling rose.m
% Called by:
%   .f90/plot_utils.make_plot
%-----------------------------------------------------------------------

path(path,'/project/dbase/web_programs/plotpro/matlab_scripts');

%pid = '02474';
cdip_rose(pid,'wave');

quit;

Source Code:

%-------------------------------------------------------------------------------
% Name:
%   .dbase/web_programs/plotpro/matlab_scripts/cdip_rose.m
% Description:
%   Creates a rose plot using parameter file data, for either
%   wind speed and wind direction, wave hs and wave direction, or
%   peak period and wave direciton.
%   Calls rose_polar.m to plot lines on polar plot.
% Called by:
%   rose_wind.m or rose_wave.m
%-------------------------------------------------------------------------------
function cdip_rose(pid, type)


% ADD PATH TO ACCESS MATLAB SCRIPTS

path(path,'/project/dbase/web_programs/plotpro/matlab_scripts');

wkg = wkg_path;


% SET-UP FIGURE

figure('position',[10 10 700 800],'visible', 'off');


% LOAD THE DATA

eval(['load ',wkg,'list.',pid,'01']);


% GET STATION INFO

info = read_info_file([pid,'01'],wkg);


% SET PARAMETERS FOR ROSE TYPE

if ( type == 'wind' )
  idx = [12,13];
  amplitude_label = 'WIND SPEED (m/s)';
  graph_title = 'WIND ROSE';
  radial_edge = 1:1:20; % bins for speed
  line_len = 0.06;
  width_delta = 5;
elseif ( type == 'wave' )
  idx = [6,8];
  amplitude_label = 'SIG WAVE HEIGHT (m)';
  graph_title = 'WAVE ROSE';
  if ( max(list(:,idx(1))) > 4 )
    radial_edge = 1:1:15; % bins for wave height
    line_len = 0.06;
    width_delta = 5;
  else
    line_len = 0.09;
    width_delta = 3;
    radial_edge = .5:.5:4; % bins for wave height
  end
else 
  idx = [7,8];
  amplitude_label = 'PEAK PERIOD (s)';
  graph_title = 'PERIOD ROSE';
  radial_edge = 2:2:30; % bins for peak period
  line_len = 0.09;
  width_delta = 2;
end

val = list(:,idx(1));
dir = list(:,idx(2));

k = find( dir >=0 & val >=0 );
if ( isempty(k) ) 
  'ERROR: no direction or value data'
  quit;
end

val = val(k);
dir = dir(k);

num_observations = length(val);
last_observation = k(length(k));
first_observation = k(1);

deg_interval = 22.5;
centers = deg_interval:deg_interval:360;
num_bins = length(centers);
% Note: this defines an extra bin
upper_edge = [deg_interval/2:deg_interval:360,360];


% TAG DIRECTION INTO BINS

[dir_sorted,I] = sort(dir);

dir_tag(1:num_observations) = -1;

k = 1;
for i=1:length(upper_edge)

  for j=k:num_observations

    if ( dir_sorted(j) <= upper_edge(i) & dir_tag(I(j)) < 0 )
      dir_tag(I(j)) = i;
    else
      k = j;
      break;
    end

  end

end


% TAG SPEED/HS INTO BINS

[val_sorted,I] = sort(val);

val_tag(1:num_observations) = -1;

k = 1;
for i=1:length(radial_edge)

  for j=k:num_observations

    if ( val_sorted(j) <= radial_edge(i) & val_tag(I(j)) < 0 )
      val_tag(I(j)) = i;
    else
      k = j;
      break;
    end

  end

end

% tag those > our max hs.

for i=1:num_observations
  if ( val_tag(I(i)) < 0 ) 
    val_tag(I(i)) = length(radial_edge) + 1;
  end
end


% MAKE A COUNT OF EACH COMBINATION, DIRECTION AND SPEED/HS

bins = zeros(length(upper_edge),length(radial_edge)+1);

for i=1:num_observations
  bins(dir_tag(i),val_tag(i)) = bins(dir_tag(i),val_tag(i)) + 1;
end


% COMBINE FIRST ROW INTO LAST ROW

bins(length(upper_edge),:) = bins(length(upper_edge),:) + bins(1,:);


% CREATE RELATIVE FREQUENCIES
% bins =
%	row - direction: 1=22.5, 2=45, ... last=360.(direction)
%	col - speed: 1=0-2, 2=2-4, ... last=18-20.  (linewidth)
%	val - frequency:                            (linelength)

bin_sum = sum(sum(bins));

bins = bins/bin_sum;

max_rho = max(sum(bins'))
start_rho = .20 * max_rho;


% CREATE INPUTS AND RUN ROSE_POLAR FOR EACH SPEED OR HEIGHT

linewidths = 2:width_delta:2+(length(radial_edge))*width_delta
colors = colormap(jet(length(radial_edge)+1));
colors(4,1) =  .5;
colors(4,3) =  .9;
centers_rad = (centers / 360) * 2 * pi;

max_col = 0;
for (col=1:length(radial_edge)+1)
  rho = [];
  theta = [];
  if ( any(bins(:,col)) )
    max_col = max(col,max_col);
    for ( row=2:length(upper_edge) )
      if ( bins(row,col) > 0 )
        if ( col > 1 )
	      prev = start_rho + sum(bins(row,1:(col-1)));
	    else
	      prev = start_rho;
        end
        rho = [  rho prev prev+bins(row,col) NaN ];    
        theta = [  theta centers_rad(row-1) centers_rad(row-1) NaN ];
      end
    end
	sz = size(theta);
	theta = theta(1,1:sz(2)-1);
	rho = rho(1,1:sz(2)-1);
    ph = rose_polar(theta, rho, '-', num_bins, max_rho+start_rho);
    hold on;
    set(ph,'linewidth',linewidths(col));
    set(ph,'color',colors(col,:));
  end
end


% RE-ORIENT AXIS SO 0=NORTH, 90=EAST (i.e. increasing clockwise)

set(gca,'cameraposition',[ 0.01 0 -100]);




% RE-ORIENT WHEEL ON FIGURE WINDOW

set(gcf,'paperposition',[.25 .5 8 10]);
% default settings: set(gca,'position',[.13 .16 .775 .815]);
set(gca,'position',[.14 .13 .70 .736129]);


% WRITE TEXT ON FIGURE, FIRST SET AXES FOR ENTIRE FIGURE REGION

ah_text = axes('position',[0 0 1 1], 'units', 'normal', 'visible', 'off');
th=text(.5,.86,graph_title, 'fontsize',30,'color',[1, .3 .3],...
  'horizontalalignment','center','fontweight','bold');
text(.5,.95,[info.stnid,' ',info.stname], 'fontsize',20,'color','blue',...
  'horizontalalignment','center');

% .94, .92, .90 -> .88 .86 .84

% CREATE START-END DATE STRING

start_string = datestr(list(first_observation,1:6));
end_string = datestr(list(last_observation,1:6));
start_string(3) = '/'; start_string(7) = '/';
end_string(3) = '/'; end_string(7) = '/';
date_string = [start_string,' - ', end_string,' UTC'];
text(.5,.925,date_string, 'fontsize',14,'color','blue',...
  'horizontalalignment','center');


% PUT NUMBER OF OBSERVATIONS

text(.5,.905,['Total Number of Occurrences = ',num2str(num_observations)], ...
  'fontsize',14,'color','blue','horizontalalignment','center');


% MAKE BLUE BOX OUTLINE AROUND PLOT

blue_box(0.01);


% PUT A LEGEND ON THE PLOT

ah_wheel = gca;  % save wheel axis for later

ax_pos = [ .03 .10 .8 .1 ];
leg_ah = axes('position',ax_pos,'visible','off','box','on');

left_start = .05;
line_height = 0;
text_y = 0;
start_line = left_start;
line_y = [ line_height line_height ];
for col=1:max_col
  if ( col == length(radial_edge)+1 )
    leg_entry = ['>',num2str(radial_edge(col-1))];
  elseif ( col == 1 )
    leg_entry = ['0-', num2str(radial_edge(col))];
  else
    leg_entry = [num2str(radial_edge(col-1)),'-',num2str(radial_edge(col))];
  end
  line_x = [start_line start_line + line_len];
  start_line = start_line + line_len;
  text_x = mean(line_x);
  text_y = linewidths(col)/65 + .15;
  th = text(text_x,text_y,leg_entry,'horizontalalignment','center');
  ph = line(line_x,line_y);
  set(ph,'linewidth',linewidths(col));
  set(ph,'color',colors(col,:));
end 
%text(line_x(2)/2,text_y+0.5,amplitude_label,'fontsize',12,...
text(left_start,text_y+0.5,amplitude_label,'fontsize',12,...
  'horizontalalignment','left');
set(gca,'xlim',[0 1.15]);
set(gca,'ylim',[-1 1]);
ax_pos(2) = .12 - linewidths(max_col)/650; 
set(gca,'position',ax_pos);


% PRINT TO PNG

set(gcf, 'visible','off');
png_name = [wkg,'plot_',pid,'.png'];
print(gcf,'-dpng','-r300',png_name);

Source Code:

function hpol = rose_polar(theta,rho,line_style,num_spokes,maxrho)
%
%
% ROSE_POLAR Specialized polar plot for wave/wind roses.
%
%   Modified from matlab's polar.m by GAC (look for GAC tags below).
%
%   ROSE_POLAR(THETA, RHO, LINE_STYLE, NUM_SPOKES) makes a plot 
%   using polar coordinates of the angle THETA, in radians, versus 
%   the radius RHO using string LINE_STYLE with NUM_SPOKES angular 
%   divisions.
%
%   Called by cdip_rose.m

if nargin < 1
    error('Requires 2 or 3 input arguments.')
elseif nargin == 2 
    if isstr(rho)
        line_style = rho;
        rho = theta;
        [mr,nr] = size(rho);
        if mr == 1
            theta = 1:nr;
        else
            th = (1:mr)';
            theta = th(:,ones(1,nr));
        end
    else
        line_style = 'auto';
    end
% GAC - debug
line_style
elseif nargin == 1
    line_style = 'auto';
    rho = theta;
    [mr,nr] = size(rho);
    if mr == 1
        theta = 1:nr;
    else
        th = (1:mr)';
        theta = th(:,ones(1,nr));
    end
end
if isstr(theta) | isstr(rho)
    error('Input arguments must be numeric.');
end
if ~isequal(size(theta),size(rho))
    error('THETA and RHO must be the same size.');
end

% get hold state
cax = newplot;
next = lower(get(cax,'NextPlot'));
hold_state = ishold;

% get x-axis text color so grid is in same color
tc = get(cax,'xcolor');
ls = get(cax,'gridlinestyle');

% Hold on to current Text defaults, reset them to the
% Axes' font attributes so tick marks use them.
fAngle  = get(cax, 'DefaultTextFontAngle');
fName   = get(cax, 'DefaultTextFontName');
fSize   = get(cax, 'DefaultTextFontSize');
fWeight = get(cax, 'DefaultTextFontWeight');
fUnits  = get(cax, 'DefaultTextUnits');
set(cax, 'DefaultTextFontAngle',  get(cax, 'FontAngle'), ...
    'DefaultTextFontName',   get(cax, 'FontName'), ...
    'DefaultTextFontSize',   get(cax, 'FontSize'), ...
    'DefaultTextFontWeight', get(cax, 'FontWeight'), ...
    'DefaultTextUnits','data')

% only do grids if hold is off
if ~hold_state

% make a radial grid
    hold on;
%   maxrho = max(abs(rho(:)));
    hhh=plot([-maxrho -maxrho maxrho maxrho],[-maxrho maxrho maxrho -maxrho]);
    set(gca,'dataaspectratio',[1 1 1],'plotboxaspectratiomode','auto')
    v = [get(cax,'xlim') get(cax,'ylim')];
    ticks = sum(get(cax,'ytick')>=0);
    delete(hhh);

% check radial limits and ticks
% GAC - modified

    minrho = min(abs(rho(:)));
    rmin = minrho; rmax = v(4); 

% GAC - modified
%   rticks = max(ticks-1,2);
    rticks = ticks;
    if rticks > 7   % see if we can reduce the number
        if rem(rticks,2) == 0
            rticks = rticks/2;
        elseif rem(rticks,3) == 0
            rticks = rticks/3;
        end
    end

% define a circle
    th = 0:pi/50:2*pi;
    xunit = cos(th);
    yunit = sin(th);
% now really force points on x/y axes to lie on them exactly
    inds = 1:(length(th)-1)/4:length(th);
    xunit(inds(2:2:4)) = zeros(2,1);
    yunit(inds(1:2:5)) = zeros(3,1);
% plot background if necessary
    if ~isstr(get(cax,'color')),
       patch('xdata',xunit*rmax,'ydata',yunit*rmax, ...
             'edgecolor',tc,'facecolor',get(gca,'color'),...
             'handlevisibility','off');
    end

% GAC - DRAW RADIAL CIRCLES

    c82 = cos(82*pi/180);
    s82 = sin(82*pi/180);
    rinc = (rmax-rmin)/rticks;

    for i= rmin:rinc:rmax

        hhh = plot(xunit*i,yunit*i,ls,'color',tc,'linewidth',1,...
                   'handlevisibility','off');

        if ( i == rmin ) 
          set(hhh,'linestyle','-','linewidth',1) 
        else
          frq = round((i-rmin)*100);
	  frq = frq/100;
          text((i-rmin+rinc)*c82,(i-rmin+rinc)*s82, ...
            num2str(frq),'verticalalignment','bottom',...
            'horizontalalignment','center','color',[0 0 1],...
            'handlevisibility','off')
        end
    end
    text((1.2*rmax)*c82,(1.2*rmax)*s82, {'frequency';'    of';'occurrence'}, ...
            'horizontalalignment','left','color',...
	    [0 0 1],'verticalalignment','bottom', ...
            'handlevisibility','off')

% GAC - MAKE OUTSIDE CIRCLE SOLID 

    set(hhh,'linestyle','-','linewidth',1);

% GAC - PLOT SPOKES AND ANNOTATE WITH DEGREE MARKERS

    rt = 1.1*rmax;
    rtt = 1.3*rmax;

    for ( th = (1/num_spokes : 1/num_spokes: 1)*2*pi )
      cst = cos(th); snt = sin(th);
      x = [ rmin*cst (rmax)*cst ];
      y = [ rmin*snt (rmax)*snt ];
      plot(x,y,ls,'color',tc,'linewidth',1,...
         'handlevisibility','off')

      spoke_degree = round(th * (180 / pi) * 10)/10;
      if ( spoke_degree == 360 ) spoke_degree = 0; end
      text(rt*cst,rt*snt,num2str(spoke_degree),...
             'horizontalalignment','center',...
             'handlevisibility','off');

    end


% GAC - PUT 'N', 'S', 'E', 'W' ON PLOT

    text(rtt*cos(0),rtt*sin(0),'N', ...
            'horizontalalignment','center',...
             'fontsize',16,...
             'color','r',...
             'handlevisibility','off');
    text(rtt*cos(pi/2),rtt*sin(pi/2),'E', ...
             'horizontalalignment','center',...
             'fontsize',16,...
             'color','r',...
             'handlevisibility','off');
    text(rtt*cos(pi),rtt*sin(pi),'S', ...
             'horizontalalignment','center',...
             'fontsize',16,...
             'color','r',...
             'handlevisibility','off');
    text(rtt*cos(-pi/2),rtt*sin(-pi/2),'W', ...
             'horizontalalignment','center',...
             'fontsize',16,...
             'color','r',...
             'handlevisibility','off');

% set view to 2-D
    view(2);

% set axis limits
    axis(rmax*[-1 1 -1.15 1.15]);

end  % if hold_state

% Reset defaults.
set(cax, 'DefaultTextFontAngle', fAngle , ...
    'DefaultTextFontName',   fName , ...
    'DefaultTextFontSize',   fSize, ...
    'DefaultTextFontWeight', fWeight, ...
    'DefaultTextUnits',fUnits );

% transform data to Cartesian coordinates.
xx = rho.*cos(theta);
yy = rho.*sin(theta);

% GAC - jul 24, 2009
% plot data on top of grid
%if strcmp(line_style,'auto')
%    q = plot(xx,yy);
%else
    q = plot(xx,yy,line_style);
%end
if nargout > 0
    hpol = q;
end
if ~hold_state
    set(gca,'dataaspectratio',[1 1 1]), axis off; set(cax,'NextPlot',next);
end
set(get(gca,'xlabel'),'visible','on')
set(get(gca,'ylabel'),'visible','on')