Hatch a plot in MATLAB | 易学教程

问题

I use this code in order to generate a graph:

And I must to hatch everything outside the square.

pos = [3.75 5.6 53.5 29.5];  %spatiul nemasurat
axis([0 61 0 45]) %axele
set(gca,'YTickLabel',{'0', '7.5','11.85', '16.2', '20.55', '24.9', '29.25', '33.6', '39.3', '45'})

rectangle('Position',pos,'EdgeColor','black')

回答1:

I made a function hatch_coordinates which can return hatch pattern coordinates (get the code at the bottom of the anwser). With that, you simply plot your hatch pattern on you axis, then you plot your rectangle on top of it. You have to set the face color of the rectangle to hide the pattern behind.

xlim = [0 61] ;
ylim = [0 45] ;
[X,Y] = hatch_coordinates( xlim , ylim ) ; %// this return coordinates to plot a hatch pattern
plot(X,Y,'k')                              %// and this simply plot the pattern, with the attributes you want (color, linespec, etc ...)
hold on ; grid off

pos = [3.75 5.6 53.5 29.5];  %spatiul nemasurat
axis([0 61 0 45]) %axele
set(gca,'YTickLabel',{'0', '7.5','11.85', '16.2', '20.55', '24.9', '29.25', '33.6', '39.3', '45'})
rectangle('Position',pos,'EdgeColor','black','FaceColor','w')

That will give you:

Note that the hatching can be varied in multiple ways. The angle can be set by changing the ratio xstep/ystep, and all the LineStyle properties are available. Quick example of a few variations:

xl = [0 5] ; yl = [0 5] ;

%// simple hatch, angle changed
[X,Y] = hatch_coordinates( xl , yl , 0.2 ) ;
subplot(1,4,1) ; plot(X,Y) ; grid off

%// heavy line hatching
[X,Y] = hatch_coordinates( xl , yl , 0.5 ) ;
subplot(1,4,2) ; plot(X,Y,'k','linewidth',2) ;grid off

%// very light color hatching, flatter angle, dotted lines
[X,Y] = hatch_coordinates( xl , yl , 1 , 0.1 ) ;
subplot(1,4,3) ; plot(X,Y,'Color',[.7 .7 .7],'linewidth',1,'LineStyle',':') ;grid off

%// multi color hatching, (specify option "merge=false" )
[X,Y] = hatch_coordinates( xl , yl , 0.5 , 0.5 , false ) ;
subplot(1,4,4) ; plot(X,Y) ;grid off

Code:

function hatch_coordinates.m :

function [X,Y] = hatch_coordinates( xlim , ylim , xstep , ystep , merge )
%// function [X,Y] = hatch_coordinates( xlim , ylim , xstep , ystep , merge )
%//
%// Return coordinates for plotting a hatch pattern
%// The angle of the lines can be adjusted by varying the ratio xstep/ystep

%% // set default options
if nargin < 3 ; xstep = 1     ; end
if nargin < 4 ; ystep = xstep ; end
if nargin < 5 ; merge = true  ; end

%% // define base grid
xpos = xlim(1):xstep:xlim(2) ; nx = numel(xpos) ;
ypos = ylim(1):ystep:ylim(2) ; ny = numel(ypos) ;

%% // Create the coordinates
nanline = NaN*ones(1,nx+ny-3) ;
X = [ [ xpos(1)*ones(1,ny-2) xpos(1:end-1) ] ; ...
      [ xpos(2:end) xpos(end)*ones(1,ny-2) ] ; ...
      nanline ] ;
Y = [ [ypos(end-1:-1:1) zeros(1,nx-2)]  ; ...
      [ypos(end)*ones(1,nx-1) ypos(end-1:-1:2)] ; ...
      nanline ] ;

%% // merge if asked too
if merge
    X = X(:) ;
    Y = Y(:) ;
end

回答2:

Is that you want to do?

if so, you should set a background color for the axis

set(gca,'color','r')

and set the facecolor of the rectangle

r=rectangle('Position',pos,'EdgeColor','black','faceColor','black')

Hope this helps.

来源：https://stackoverflow.com/questions/29949205/hatch-a-plot-in-matlab

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