Matlab实现天线场图、波瓣图

%************************************************************************** % polar_dB(theta,rho,rmin,rmax,rticks,line_style) %************************************************************************** % POLAR_DB is a MATLAB function that plots 2-D patterns in % polar coordinates where: % 0 <= THETA (in degrees) <= 360 % -infinity < RHO (in dB) < +infinity % % Input Parameters Description % ---------------------------- % - theta (in degrees) must be a row vector from 0 to 360 degrees % - rho (in dB) must be a row vector % - rmin (in dB) sets the minimum limit of the plot (e.g., -60 dB) % - rmax (in dB) sets the maximum limit of the plot (e.g., 0 dB) % - rticks is the # of radial ticks (or circles) desired. (e.g., 4) % - linestyle is solid (e.g., '-') or dashed (e.g., '--') % % Credits: % S. Bellofiore % S. Georgakopoulos % A. C. Polycarpou % C. Wangsvick % C. Bishop % % Tabulate your data accordingly, and call polar_dB to provide the % 2-D polar plot % % Note: This function is different from the polar.m (provided by % MATLAB) because RHO is given in dB, and it can be negative %----------------------------------------------------------------------------- function hpol = polar_dB(theta,rho,rmin,rmax,rticks,line_style) % Convert degrees into radians theta = theta * pi/180; % Font size, font style and line width parameters font_size = 16; font_name = 'Times'; line_width = 1.5; if nargin < 5 error('Requires 5 or 6 input arguments.') elseif nargin == 5 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 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 any(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'); % 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'); set(cax, 'DefaultTextFontAngle', get(cax, 'FontAngle'), ... 'DefaultTextFontName', font_name, ... 'DefaultTextFontSize', font_size, ... 'DefaultTextFontWeight', get(cax, 'FontWeight') ) % only do grids if hold is off if ~hold_state % make a radial grid hold on; % v returns the axis limits % changed the following line to let the y limits become negative hhh=plot([0 max(theta(:))],[min(rho(:)) max(rho(:))]); v = [get(cax,'xlim') get(cax,'ylim')]; ticks = length(get(cax,'ytick')); delete(hhh); % check radial limits (rticks) if rticks > 5 % 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)]; xunits(inds(2:2:4)) = zeros(2,1); yunits(inds(1:2:5)) = zeros(3,1); rinc = (rmax-rmin)/rticks; % label r % change the following line so that the unit circle is not multiplied % by a negative number. Ditto for the text locations. for i=(rmin+rinc):rinc:rmax is = i - rmin; plot(xunit*is,yunit*is,'-','color',tc,'linewidth',0.5); text(0,is+rinc/20,[' ' num2str(i)],'verticalalignment','bottom' ); end % plot spokes th = (1:6)*2*pi/12; cst = cos(th); snt = sin(th); cs = [-cst; cst]; sn = [-snt; snt]; plot((rmax-rmin)*cs,(rmax-rmin)*sn,'-','color',tc,'linewidth',0.5); % plot the ticks george=(rmax-rmin)/30; % Length of the ticks th2 = (0:36)*2*pi/72; cst2 = cos(th2); snt2 = sin(th2); cs2 = [(rmax-rmin-george)*cst2; (rmax-rmin)*cst2]; sn2 = [(rmax-rmin-george)*snt2; (rmax-rmin)*snt2]; plot(cs2,sn2,'-','color',tc,'linewidth',0.15); % 0.5 plot(-cs2,-sn2,'-','color',tc,'linewidth',0.15); % 0.5 % annotate spokes in degrees % Changed the next line to make the spokes long enough rt = 1.1*(rmax-rmin); for i = 1:max(size(th)) text(rt*cst(i),rt*snt(i),int2str(abs(i*30-90)),'horizontalalignment','center' ); if i == max(size(th)) loc = int2str(90); elseif i*30+90<=180 loc = int2str(i*30+90); else loc = int2str(180-(i*30+90-180)); end text(-rt*cst(i),-rt*snt(i),loc,'horizontalalignment','center' ); end % set viewto 2-D view(0,90); % set axis limits % Changed the next line to scale things properly axis((rmax-rmin)*[-1 1 -1.1 1.1]); end % Reset defaults. set(cax, 'DefaultTextFontAngle', fAngle , ... 'DefaultTextFontName', font_name, ... 'DefaultTextFontSize', fSize, ... 'DefaultTextFontWeight', fWeight ); % transform data to Cartesian coordinates. % changed the next line so negative rho are not plotted on the other side for i = 1:length(rho) if (rho(i) > rmin) if theta(i)*180/pi >=0 & theta(i)*180/pi <=90 xx(i) = (rho(i)-rmin)*cos(pi/2-theta(i)); yy(i) = (rho(i)-rmin)*sin(pi/2-theta(i)); elseif theta(i)*180/pi >=90 xx(i) = (rho(i)-rmin)*cos(-theta(i)+pi/2); yy(i) = (rho(i)-rmin)*sin(-theta(i)+pi/2); elseif theta(i)*180/pi < 0 xx(i) = (rho(i)-rmin)*cos(abs(theta(i))+pi/2); yy(i) = (rho(i)-rmin)*sin(abs(theta(i))+pi/2); end else xx(i) = 0; yy(i) = 0; end end % 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 axis('equal');axis('off'); end % reset hold state if ~hold_state, set(cax,'NextPlot',next); end