Adding titles squashes one of my images in a TiledChartLayout (R2020a)

I have a TiledChartLayout of 6 images that initially looks like this:

Then, however, I add titles to the upper 5 images and it squashes the lower image to a flat line, resulting in this:

I tried resizing the figure, to no avail. Why might this be happening and how do I prevent it?

[Matt J]

Here is a code that will reproduce the effect (in R2020a)

h=openfig('testFig');

str='ABCDE';

ax=flip(findobj('Type','axes'));

for i=1:5,  title(ax(i),str(i)); ax(i).FontSize=15; end

figure(h)

[Fangjun Jiang]

I checked the value of ax.Position after each loop. It changed after title was added to the first row and second row. It squeezed the third row.

[Matt J]

But shouldn't it not do that? Shouldn't the inner positions of the axes contract to preserve the outer positions when the position constraint parameter of the layout is set to 'outerposition'?

>> TL=get(gcf,'Children'); TL.PositionConstraint

ans =

    'outerposition'

[Fangjun Jiang]

Maybe pre-set the title of the axes? Someone must give up something (the real estate in the figure).

From documentation,

PositionConstraint — Position to hold constant

'outerposition' | 'innerposition'

Position property to hold constant when adding, removing, or changing decorations

Note

Setting this property has no effect when the parent container is a TiledChartLayout.

[Matt J]

Maybe pre-set the title of the axes?

Same result...

[Matt J]

Seems to work fine in R2021a:

h=openfig('testFig');

str='ABCDE';

ax=flip(findobj('Type','axes'));

for i=1:5,  title(ax(i),str(i)); ax(i).FontSize=15; end

h.Position(4)=1.1*h.Position(4);
figure(h)

Answer 1

[Benjamin Kraus]

I opened the figure you created, and I see you have set the GridSize to [2756 3840].

TiledChartLayout is attempting to keep each of those axes the same height, so when you add a title to any axes in the second row it is going to make space for a title on all 2755 rows in between the axes.

A better approach is to leverage the south tile of the TiledChartLayout.

Generically:

t = tiledlayout('flow');
for i = 1:5
    ax(i) = nexttile(t);
    imagesc(ax(i),rand(100));
    axis(ax(i),'off','square');
    title(ax(i), char('@'+i));
    ax(i).FontSize = 15;
end
ax(6) = axes(t);
imagesc(ax(6),linspace(0,1,256).*[1;1]);
colormap(t.Parent, gray);
ax(6).Layout.Tile = 'south';
pbaspect(ax(6),[20 1 1])
axis(ax(6),'off')

Or better yet, use the regular colorbar:

t = tiledlayout('flow');
for i = 1:5
    ax(i) = nexttile(t);
    imagesc(ax(i),rand(100));
    axis(ax(i),'off','square');
    title(ax(i), char('@'+i));
    ax(i).FontSize = 15;
end
colormap(t.Parent, gray);
c = colorbar;
c.Layout.Tile = 'south';

[Matt J]

Hi Benjamin,

Thanks for your response, but I'm afraid neither of those solutions work in R2020a. With your generic solution, I see no colorbar. With your second suggestion, I get

Unrecognized method, property, or field 'Layout' for class 'matlab.graphics.illustration.ColorBar'.

Error in test (line 12)
c.Layout.Tile = 'south';

As I pointed out in my comment above, the problem is solvable in R2021a (but not in R2020a) by resizing the figure that I originally posted. Are you able to reproduce this difference between R2020a and R2021a?

[Benjamin Kraus]

@Matt J TiledChartLayout first shipped in R2019b, but there have been some bug fixes and improvements over the past few releases. One improvement (made in R2020b) is in how TileChartLayout handles axes with constrained plot box aspect ratios. The Colorbar gained the Layout property in R2020b as well.

[Matt J]

Then, is there any workaround that will let me constrain plot box aspect ratios in 2020a?