Getting hatchfill to properly display a patch legend

I'm using hatchfill to create patterned hatches, as the above example illustrates.

However the legend shows a line rather than a patch. Is there any way to make it show a patch?

The attached image shows the output of the code below. The legend icon for the hatch patch should

look like the icon for the regular hatch

obj.X = 1 + [0, 0 , 1 , 1 ]
obj.Y = 1 + [0, 1 , 1 , 0 ]
obj.FaceColor	= 'b';
obj.FaceAlpha	= 0.4;
obj2.X = [0, 0 , 1/2 , 1/2 ]
obj2.Y = [0, 1/2 , 1/2 , 0 ]
obj2.FaceColor	= 'g';
obj2.FaceAlpha	= 0.4;

h 		= patch(obj);
k 		= patch(obj2);
hatchObj= hatchfill(h);
set(gca,'XLim',[0,3]);
set(gca,'YLim',[0,3]);
legend('hatch patch','patch')

Answer 1

[Leo Simon]

It turns out that the problems I described in my original question can all be resolved by using the legendflex and hatchfill2 packages.

Here's an extension of my original code, and the picture that it generates.

clear all;close all
%parameters of the first patch object
obj(1).X = 1 + [0, 0 , 1 , 1 ];
obj(1).Y = 1 + [0, 1 , 1 , 0 ];
obj(1).FaceColor	= 'b';
obj(1).FaceAlpha	= 0.2;
HatchColor{1}		= [0.4,0.4,0.4];
HatchAngle{1}		= 20;
HatchType{1}		= 'single';
HatchDensity{1}		= 20;

%Parameters of the first patch object
obj(2).X = 0.5*[0, 0 , 1 , 1 ];
obj(2).Y = 0.5*[0, 1 , 1 , 0 ];
obj(2).FaceColor	= 'g';
obj(2).FaceAlpha	= 0.2;
HatchColor{2}		= [1,0,0];
HatchAngle{2}		= 20;
HatchDensity{2}		= 10;
HatchType{2}		= 'cross';

%make the patches
for ii=1:2;
	h(ii) 		= patch(obj(ii));
end; 

%hatch the patches
for ii=1:2;
	hHatch(ii) 	= hatchfill2(h(ii),HatchType{ii},...
					'HatchAngle',HatchAngle{ii},...
					'HatchDensity',HatchDensity{ii},...
					'HatchColor',HatchColor{ii});
end;

%Make the legend
Legend  			= {'blue square','green square'};
[legend_h,object_h,plot_h,text_str] = legendflex(h,Legend,...
 						'anchor',{'se','se'},...  
						'buffer',[-90, 60 ],... 
						'fontSize',20);
%object_h is the handle for the lines, patches and text objects

%hatch the legend patches to match the patches 
for ii=1:2;
	hHatch(ii+2) 	= hatchfill2(object_h(ii+2),HatchType{ii}, ...
					'HatchAngle',HatchAngle{ii},...
					'HatchDensity',HatchDensity{ii},...
					'HatchColor',HatchColor{ii});
end;

%I couldn't use hatchfill2 to set the FaceAlpha's so I did it manually
for ii= 1:2
	object_h(ii+2).FaceAlpha = obj(ii).FaceAlpha;  
end;

[JS]

Hi Leo,

I tried out your code and it didn't work. I'm getting an error in line 465 in the legendflex function. The error reads:

Check for missing argument or incorrect argument data type in call to function 'getpos'.

Error in legendflex (line 465)

legpospx = getpos(h.leg, 'px');

I'm wondering if this is due to the version of Matlab I'm using which is R2020a (Update 7 9.8.0.172...). I can't seem to figure out what argument that might be missing from your code in regard to using a newer version. Any suggestions?

Kind regards,

Jared

[Simeon]

Hi, this issue occurs because legendflex.m comes with a getpos.m, which you also need inside your directory.

[Sille Petrine Vest Hansen]

Hi

I have a issue with the getpos.m function:

Unary operator '~' is not supported for operand of

type 'matlab.ui.Figure'.

Error in getpos (line 160)

if ~href % HREF is the Root object (no 'Position' property)

Error in legendflex (line 465)

legpospx = getpos(h.leg, 'px');

Error in test (line 12)

[legend_h, object_h, plot_h, text_str] = legendflex(bars, legendData, 'Padding', [2, 2, 10], 'FontSize', 18, 'Location', 'NorthEast');

I have the same issue in my own script, but I have also tested the shown script, and the same problem occurs.

Do you know, why this is an issue?

[DGM]

What version of that file are you using? The getpos() version 1.2 that's currently included with legendflex() doesn't have that test on line 160, and the test in question isn't written that way.

You might want to check with

which getpos -all

to see if there's an older copy that may have come from somewhere else.

Answer 2

[Simeon]

Here's an example.

With its corresponding code.

% Requirements to get this working:
%     hatchfill2.m: https://github.com/hokiedsp/matlab-hatchfill2/blob/master/hatchfill2.m
%     legendflex.m: https://github.com/kakearney/legendflex-pkg/blob/master/legendflex/legendflex.m
%     getpos.m: https://github.com/kakearney/legendflex-pkg/blob/master/setgetpos_V1.2/getpos.m

hold on;
bar1 = bar(1, 100, 'FaceColor', 'white');
bar2 = bar(2, 50, 'FaceColor', 'white');

% Keep an array of the plots so that none of the hatchfill2 lines appear in the legend
bars = [bar1, bar2];

% Hatch the two bars with a texture
hatchfill2(bar1(1), 'cross', 'HatchAngle', 45, 'HatchDensity', 60, 'HatchColor', 'black');
hatchfill2(bar2(1), 'single', 'HatchAngle', 45, 'HatchDensity', 40, 'HatchColor', 'black');

% Draw the legend
legendData = {'Bar #1', 'Bar #2'};
[legend_h, object_h, plot_h, text_str] = legendflex(bars, legendData, 'Padding', [2, 2, 10], 'FontSize', 18, 'Location', 'NorthEast');
% object_h(1) is the first bar's text
% object_h(2) is the second bar's text
% object_h(3) is the first bar's patch
% object_h(4) is the second bar's patch
%
% Set the two patches within the legend
hatchfill2(object_h(3), 'cross', 'HatchAngle', 45, 'HatchDensity', 60/4, 'HatchColor', 'black');
hatchfill2(object_h(4), 'single', 'HatchAngle', 45, 'HatchDensity', 40/4, 'HatchColor', 'black');

% Some extra formatting to make it pretty :)
set(gca, 'FontSize', 18);
set(gca, 'XMinorTick','on', 'XMinorGrid','on', 'YMinorTick','on', 'YMinorGrid','on');
xlim([0, 3]);
ylim([0, 110]);

I hope this helps someone out there!

[Zafimandimby Mampiandra]

I cannot use the function "hatchfill2" it shows that it is not defined.

Can you please help me o solve this problem?

Thanks

[Simeon]

Hi Zafimandimby, Try running the hatchfill.m file so that Matlab recognizes its functions, then run your plotting script to use those functions.

Answer 3

[kailin gong]

Hi, I use hatchfill2 to plot a mixed graph, but I feel confused about how to display a patch legend with other style legend, such as line.

Based on the previous mentioned code.

I add a line：

line=plot([1,2],[5,10]);

I changed the legend：

legendData = {'Bar #1', 'Bar #2', 'Line'};

Then I changed：

[legend_h, object_h, plot_h, text_str] = legendflex([bars, line], legendData, 'Padding', [2, 2, 10], 'FontSize', 18, 'Location', 'NorthEast');

It turns out an error：

Error using hatchfill2>parse_input (line 856)
Unsupported graphics handle type.
Error in hatchfill2 (line 98)
[A,opts,props] = parse_input(A,varargin);

Please help, thanks in advance.

[Simeon]

Hi Kailin, that's a great question which highlights how the legendflex works.

Try plotting again but type this into the terminal: "object_h", it'll give an output like this:

Text     (Bar #1)
Text     (Bar #2)
Text     (Line)
Group    (Bar #1)
Group    (Bar #2)
Line     (Line)
Line     (Line)

So you now know that the two legendflex indexes that you want are 4 and 5 (not 3 and 4), look for:

4: Group    (Bar #1)
5: Group    (Bar #2)

So once you apply the hatchfill2 to those two legend patches, like so:

hatchfill2(object_h(4), 'cross', 'HatchAngle', 45, 'HatchDensity', 60/4, 'HatchColor', 'black');
hatchfill2(object_h(5), 'single', 'HatchAngle', 45, 'HatchDensity', 40/4, 'HatchColor', 'black');

You should no longer get any error. The full code will look something like this:

% Requirements to get this working:
%     hatchfill2.m: https://github.com/hokiedsp/matlab-hatchfill2/blob/master/hatchfill2.m
%     legendflex.m: https://github.com/kakearney/legendflex-pkg/blob/master/legendflex/legendflex.m
%     getpos.m: https://github.com/kakearney/legendflex-pkg/blob/master/setgetpos_V1.2/getpos.m
hold on;
bar1 = bar(1, 100, 'FaceColor', 'white');
bar2 = bar(2, 50, 'FaceColor', 'white');
line = plot([0, 1, 2, 3], [50 30, 60, 30], 'Color', '#615285', 'LineWidth', 3)
% Keep an array of the plots so that none of the hatchfill2 lines appear in the legend
plots = [bar1, bar2, line];
% Hatch the two bars with a texture
hatchfill2(bar1(1), 'cross', 'HatchAngle', 45, 'HatchDensity', 60, 'HatchColor', 'black');
hatchfill2(bar2(1), 'single', 'HatchAngle', 45, 'HatchDensity', 40, 'HatchColor', 'black');
% Draw the legend
legendData = {'Bar #1', 'Bar #2', 'Line'};
[legend_h, object_h, plot_h, text_str] = legendflex([plots, line], legendData, 'Padding', [2, 2, 10], 'FontSize', 18, 'Location', 'NorthEast');
% object_h(1) is the first bar's text
% object_h(2) is the second bar's text
% object_h(3) is the third line text
% object_h(4) is the first bar's patch
% object_h(5) is the second bar's patch
% object_h(6) is the third line patch

% Set the two patches within the legend
hatchfill2(object_h(4), 'cross', 'HatchAngle', 45, 'HatchDensity', 60/4, 'HatchColor', 'black');
hatchfill2(object_h(5), 'single', 'HatchAngle', 45, 'HatchDensity', 40/4, 'HatchColor', 'black');
% Some extra formatting to make it pretty :)
set(gca, 'FontSize', 18);
set(gca, 'XMinorTick','on', 'XMinorGrid','on', 'YMinorTick','on', 'YMinorGrid','on');
xlim([0, 3]);
ylim([0, 110]);

Hope this helps.

Simeon

[kailin gong]

So nice of you, thanks very much. I found another problem, when I change the 'Location' to 'southwest', there is no any change for the legend location. Is there anything wrong with the legendflex function?

[legend_h, object_h, plot_h, text_str] = legendflex([plots, line], legendData, 'Padding', [2, 2, 10], 'FontSize', 18, 'Location', 'southwest');

[Simeon]

Right, the positioning for legendflex is strange also, if you look here:

• https://www.mathworks.com/matlabcentral/fileexchange/31092-legendflex-m-a-more-flexible-customizable-legend#readme

You'll see that:

• North --> 'anchor', [2 2], 'buffer', [0 -10]
• South --> 'anchor', [6 6], 'buffer', [0 10]
• East --> 'anchor', [4 4], 'buffer', [-10 0]
• West --> 'anchor', [8 8], 'buffer', [10 0]
• NorthEast --> 'anchor', [3 3], 'buffer', [-10 -10]
• NorthWest --> 'anchor', [1 1], 'buffer', [10 -10]
• SouthEast --> 'anchor', [5 5], 'buffer', [-10 10]
• SouthWest --> 'anchor', [7 7], 'buffer', [10 10]
• NorthOutside --> 'anchor', [2 6], 'buffer', [0 10]
• SouthOutside --> 'anchor', [6 2], 'buffer', [0 -10]
• EastOutside --> 'anchor', [3 8], 'buffer', [10 0]
• WestOutside --> 'anchor', [8 3], 'buffer', [-10 0]
• NorthEastOutside --> 'anchor', [3 1], 'buffer', [10 0]
• NorthWestOutside --> 'anchor', [1 3], 'buffer', [-10 0]
• SouthEastOutside --> 'anchor', [5 7], 'buffer', [10 0]
• SouthWestOutside --> 'anchor', [7 5], 'buffer', [-10 0]

Also, when saving the figure use ctrl+s instead of clicking the save icon, since unlike the traditional legend, the legendflex legend is its own figure, so you gotta save both of together to have the legend show up in the resulting plot.

[Ralph van Zwieten]

Hi Simeon,

I have a related question. I am trying to apply the hatchfill to a stacked bar plot that I have, where I keep on running into several errors.

Could you maybe have a look at it?:

LO = [0.1, 0.2, 0.3, 0.4];

OLO = [0.2, 0.3, 0.4, 0.1];

RGO = [0.3, 0.4, 0.1, 0.2];

SFO = [0.4, 0.1, 0.2, 0.3];

comp = [LO; OLO; RGO];% SFO];

comp = oil_comp*100; %

oi = categorical ({'Li', 'Ol', 'Ri'});%, 'Su'});

oi = reordercats(oi, {'Li', 'Ol', 'Ri'});%, 'Su'});

str = {'Li', 'Ol', 'Ri'};

Y= oil_comp;

bar(oi, Y, 'stacked');

ylim([0 102])

ax = get(gca);

cat = ax.Children;

set(cat(4),'FaceColor',[21 96 189]/255);

set(cat(3),'FaceColor',[30 144 255]/255);

set(cat(2),'FaceColor',[130,238,253]/255);

%set(cat(1),'FaceColor',[173 216 230]/255);

set(cat(1),'FaceColor',[255 204 203]/255);

% Hatch the two bars with a texture

hatchfill2(cat(1), 'single', 'HatchAngle', 45, 'HatchDensity', 60, 'HatchColor', 'black');

hatchfill2(cat(2), 'single', 'HatchAngle', 45, 'HatchDensity', 40, 'HatchColor', 'black');

Ultimately, I would like to have the bottom box of every bar with the same hatch density , and then increasing density when going to the boxes above that.

If you know how to give every box an individual color, so having 12 instead of 4 different colors), that would be great to hear as well!

Hopefully you can help me out, thank you in advance.

Answer 4

[Asvin Kumar]

I presume you’re using the hatchfill function from File Exchange.

Internally, it calls the line function to create the hatch patterns. See lines 171 and 176 of the source code. It follows that the legend would only show line and patch. With this hatchfill function it won’t be possible to change the legend.

[Leo Simon]

Thanks Asvin, I've switched to hatchfill2 and combined it will legendflex. This combination enables me to do pretty much whatever I need. I've answered my own question below.

[Christopher Bitikofer]

checking out legendflex. Thanks Leo for posting this!!!